Sle234 Microbiology

Front 1

what is microbiology?

Back 1

the study of microorganisms and their activities

Front 2

what is biomass?

Back 2

the earths living material

Front 3

what does biomass consist of?

Back 3

-Microorganisms (50%)
-plants (35%)
-animals (15%)

Front 4

90% of the cells in our body are:

Back 4

bacterial (prokaryotic derived)

Front 5

how many characteristics do microorganisms have?

Back 5

seven

Front 6

what are the 7 characteristics of microorganisms?

Back 6

1. mostly unicellular
2.metabolise
3. reproduce
4. differentiate
5. communicate
6. movement
7. evolution

(MMRDCME)

Front 7

what does it mean to differentiate

Back 7

alter form of function

Front 8

what does it mean to respond to chemical signals in environment (produced by other cells)

Back 8

communicate

Front 9

what does it mean to ingest/assimilate nutrients/chemicals, transform ingested material, release energy, excrete waste products?

Back 9

metabolise

Front 10

what does it mean to biochemically synthesise more cells?

Back 10

reproduce

Front 11

what does it mean when a living organisms are often capable of self propolsion

Back 11

movement

Front 12

what does it mean when cells evolve to display new biological properties, phylogenetic trees show the evolutionary relationships between cells?

Back 12

evolution (Evolve)

Front 13

out of the 7 characteristics of microorganisms, which ones distinguish living cells from non-living chamical systems?

Back 13

2 to 7
(metabolism, reproduce, differentiate, communicate, move, evolve)

Front 14

what are the 5 major groups of Microorganisms, and what is the 6th extra one?

Back 14

1. Algae
2. Fungi
3. Protozoa
4. Bacteria
5. Blue-green algae

and the extra one is
6.Archaea

(keyword: AFPBBA)

Front 15

cells are divided into which two main types?

Back 15

Eukaryotes and Prokaryotes

Front 16

what cell has the genetic material (DNA) enclosed within a nucleus,

and possesses functional compartments (organelles)?

Back 16

Eukaryotes

Front 17

What cell does not have the DNA enclosed in a membrane and does not have organelles?

Back 17

Prokaryotes

Front 18

what are the three domains of life?

Back 18

Domain of Bacteria
Domain of Archaea
Domain of Eukarya

Front 19

what does the domain of bacteria contain?

Back 19

5 different branches:

Spirocheles
Chlemydiac
Gram-positive bacteria
Cyano-bacteria

Front 20

what does the domain of Archaea contain?

Back 20

three different branches:

Methanogens
Extreme halophiles
Extreme thermophiles

Front 21

what does the domain of Eukarya contain?

Back 21

Eukaryotes

Front 22

what is the conquest of disease?

Back 22

pathogenic bacteria cause major and minor diseases which have affected human history

Front 23

what are the 4 reasons to study bacteria?

Back 23

1. The conquest of disease
2. the food industry
3. Biotechnology (for DNA manipulation), MEdicine (antibiotics), industry, agriculture (microbial insecticides)
4. natural element cycles (C, n, S affect fertility and structure of soil)

Front 24

what is the meaning of Bioremediation?

Back 24

Bioremediation is a waste management technique that involves the use of organisms to remove or neutralize pollutants from a contaminated site

Front 25

what were some of the phenomena caused by micro-organisms attributed to, according to old theories that were proven wrong?

Back 25

-A supreme bening
-magic
-Chemical instabilities
-Spontaneous generation (the idea that non-living material can give rise to living organisms)

Front 26

what is the old theory of spontaneous generation?

Back 26

the idea that non-living material can give rise to living organisms

Front 27

in 1680 Leeuwenhoek made a microscope and described:

Back 27

Leeuwenhoek's described "animalcules" and believed that organisms arose from preexisting ones (Biogenesis) and he described life's smallest structural units as "little boxes" or "cells".

Front 28

what are the scientist behind the findings on spontaneous generation

Back 28

-great philosophers favoured spontaneous generation

-1745-John Needham stated that if boiled broth was cooled and placed in a flask, then organisms soom appeared

-Spallanzani (1729-99) however suggested that microorganisms from the air contaminated Needhams brother, he demonstarted that if broth was heated in a Sealed flask then there was no growth

-Needham claimed that a vital force such as air, oxygen was destroyed by heating and kept out of the sealed flask

-100 years until Pasteur devised a method to test air, where he showed that microorganisms were in the air too, and so in 1862, Louis Pasteur showed that life does not arise through spontaneous generation but rather came from life itself (Biogenesis)

Front 29

What did Louis pasteur's discovery give to modern day sterilisation concepts?

Back 29

when he did the experiment with the swan necked flask, so germs present in air (dust) with the amount varying with temperature, moisture and movement which showed the importance of sterilisation

Front 30

what year did Louis pasteur immunise farm animals against anthrax and cholera?

Back 30

1865-1885

Front 31

in 1843-1910 what did Robert Koch show?

Back 31

that blood of anthrax-infected animals was teaming with bacteria (bacillus anthracis), which arose the thought and finding that yes, bacteria were the cause of anthrax

Front 32

what is the difference between basic and applied microbiology? (1.1)

Back 32

Microorganisms, which include all single-celled microscopic organisms and the viruses, are essential for the well-being of the planet and its plants and animals

Front 33

cells can be thought of as both catalysts and genetic entities. Explain how these two attributes of a cell differ (2.1)

Back 33

Metabolism, growth, and evolution are necessary properties of living systems. Cells must coordinate energy production and consumption with the flow of genetic information during cellular events leading up to cell division

Front 34

what is an ecosystem? What effects can microorganisms have on their ecosystems? (1.3)

Back 34

Microorganisms exist in nature in populations that interact with other populations in microbial communities. the activities of microorganisms in microbial communities can greatly affect and rapidly change the chemical and physical properties of their habitats

Front 35

Why did the evolution of cyanobacteria change earth forever (1.4)

Back 35

Diverse microbial populations were widespread on earth for billions of years before higher organisms appeared, and cyanobacteria in particular were important because they oxygenated the atmosphere. The cumulative microbial biomass on Earth exceeds that of higher organisms, and most microorganisms reside in the deep subsurface. Bacteria, Archaea, and Eukarya are the major phylogenetic lineages of cells

Front 36

how would you convince a friend that microorganisms are much more than just agents of disease? (1.5)

Back 36

Microorganisms can be both beneficial and harmful to humans, although many more microorganisms are beneficial or even essential that are harmful

Front 37

For what contributions are Hooke, van Leeuwenhoek, and Ferdinand Cohn most remembered in microbiology? (1.6)

Back 37

Robert Hooke was the first to describe microorganisms, and Antoni van Leeuwenhoek was the first to describe bacteria.
Ferdinand Cohn founded the field of bacteriology and discovered bacterial endospores

Front 38

Explain the principles behind the use of the Pasteur flask in studies on spontaneous generation (1.7)

Back 38

Louis Pasteur is best remembered for his ingenious experiments showing that living organisms do not arise spontaneously from nonliving matter. He developed many concepts and techniques central to the science of microbiology, including sterilization

Front 39

What are Koch's postulates and how did they influence the development of microbiology? why are Koch's postulates still relevant today? (1.8)

Back 39

Robert Koch developed a set of criteria anchored in experimentation-Koch's postulates- for the study of infectious diseases and developed the first methods for growth of pure cultures of microorganisms

Front 40

In contrast to those of Robert Koch, what were the major microbiological interests of Martinus Beijerinck and Sergei Winogradsky? (1.9)

Back 40

Beijerinck and Winogradsky studied bacteria that inhabit soil and water. Out of their work came the enrichment culture technique and the concepts of chemolithotrophy and nitrogen fixation

Front 41

How does the genomics revolution propel advances in microbiology? (1.10)

Back 41

In the middle to latter part of the twentieth century, basic and applied sub disciplines of microbiology emerged; these have led to the current era of molecular microbiology

Front 42

what is the fundemental unit of living matter?

Back 42

the cell

Front 43

what is a form of metabolism in which energy is generated from inorganic compounds?

Back 43

Chemolithotrophy

Front 44

what are interactions between cells using chemical signals?

Back 44

Cell communication

Front 45

what are modifications of cellular components to form a new structure, such as a spore?

Back 45

Differentiation

Front 46

What is a method for isolating specific microorganisms from nature using specific culture media and incubation conditions

Back 46

Enrichment culture technique

Front 47

what is a protein (or in some cases RNA) catalyst that functions to speed up chemical reactions?

Back 47

Enzyme

Front 48

what has a descent with modification leading to new forms or species?

Back 48

Evolution

Front 49

What is an organisms full complement of genes?

Back 49

Genome

Front 50

what is the identification and analysis of genomes?

Back 50

Genomics

Front 51

in microbiology, what is an increase in cell number with time?

Back 51

Growth

Front 52

what is the environment in which a microbial population resides?

Back 52

Habitat

Front 53

what is a set of criteria for proving that a given microorganism causes a given disease?

Back 53

Koch's postulates

Front 54

all biochemical reactions in a cell is called

Back 54

metabolism

Front 55

two or more populations of cells that coexist and interact in a habitat is called a

Back 55

microbial community

Front 56

what is the study of microorganisms in their natural environments?

Back 56

Microbial ecology

Front 57

what is a microscopic organisms consisting of a single cell or cell cluster or a virus?

Back 57

Microorganism

Front 58

What is the movement of cells by some form of self-propulsion?

Back 58

Motility

Front 59

What is a disease causing microorganism?

Back 59

Pathogen

Front 60

what is a culture containing a single kind of microorganism?

Back 60

Spontaneous generation

Front 61

what is free of all living organisms (cells) and viruses?

Back 61

Sterile

Front 62

What important biochemical process takes place within these structures found on the roots of legumes?

Back 62

Nitrogen fixation

Front 63

When considering the properties of all cellular life, what two ways can cells be viewed?

Back 63

Biochemical catalysts and genetic coding devices

Front 64

Who is the scientist that discovered endospores?

Back 64

Cohn

Front 65

A colony on a Petri plate arises from a single cell. How many cells does a typical bacterial colony contain?

Back 65

10^7

Front 66

What type of glassware was used in the experiments that settled the controversy surrounding spontaneous generation?

Back 66

Swan-necked flask

Front 67

For which type of disease today is it occasionally impossible to satisfy Koch's postulates?

Back 67

Lethal infectious diseases that only occur in humans

Front 68

Which model system did Robert Koch utilize to prove the causative agent of tuberculosis?

Back 68

Guinea pigs

Front 69

Who showed that viruses were filterable agents that were smaller than bacteria?

Back 69

Beijerinck

Front 70

What is chemolithotrophy?

Back 70

The oxidation of inorganic compounds linked to energy conservation within a cell

Front 71

Which types of organisms are the most important for the maintenance of life on Earth?

Back 71

Microorganisms

Front 72

Consider the following two statements:
Ecosystems are influenced by microbial activities.
Microbial ecosystems remain constant over time.
which statement is correct?

Back 72

Only statement I is correct

Front 73

Which of the following characteristics was found in the earliest cellular organisms?

Back 73

Anaerobic metabolism

Front 74

What is the process called when proteins are synthesized based on information from an RNA molecule?

Back 74

Translation

Front 75

When does the preponderance of evidence suggest that life first arose on Earth?

Back 75

~ 3.8 × 109 years ago

Front 76

Which early microbiologist studied the large filamentous sulfur bacterium, later called Beggiatoa?

Back 76

Ferdinand Cohn

Front 77

What is the second of Koch's postulates?

Back 77

The organism must initially be cultivated in pure culture away from the animal body.

Front 78

Who isolated in pure culture the first nitrogen-fixing bacterium?

Back 78

Winogradsky

Front 79

What plant-like characteristic do chemolithotrophs possess?

Back 79

They are autotrophs.

Front 80

how many mm and m are in 1 micro meter?

Back 80

10^-3 mm and 10^-6m

Front 81

how many micro meters and meters are in 11 nm?

Back 81

1nm = 10^-3 micro meters and
10^-9 meters

Front 82

how many nm and m are in 1 Armstrong?

Back 82

10^-1 nm and 10^-10

Front 83

most bacterial cells are between what diameter?

Back 83

0.5 to 1.0 micro meters in diameter

Front 84

light microscope cant resolve objects smaller than

Back 84

~0.2 micro meters

Front 85

what is the maximum enlargement in regards to magnification on microscope?

Back 85

meximum enlargement depends on how close the object can be brought to eye and remain in focus (~25cm)

Front 86

objects smaller than what cannot be seen distinctly

Back 86

0.1mm

Front 87

what do microscopes do for the retina?

Back 87

microscopes increase retinal surface area occupied by image, there are specific lenses to magnify image

Front 88

What is Resolution?

Back 88

the ability to distinguish 2 adjacent points as separate

Front 89

what does resolution depend on?

Back 89

resolution depends on the physical properties of light, so resolution defines limit of what can be seen with the microscope

Front 90

how many lenses are on a simple microscope?

Back 90

a simple microscope is essentially a microscope with one lens only around 5X (Leeuwenhoeks lense was 300X)

Front 91

the compound microscope was invented by

Back 91

Zacharias Janssen

Front 92

what is the compound microscope?

Back 92

a bright field, or light microscope (the most basic type of compound scope) which uses visible light to view object

Front 93

how are specimens made visible with the compound microscope?

Back 93

by differences in contrast between them and the surrounding medium

Front 94

what is the contrast due to in a compound microscope? and what does this form?

Back 94

contrast is due to absorption or scattering of light by specimen, this forms a bright image against a darker background

Front 95

what microscope uses a series of lenses?

Back 95

the compound microscope

Front 96

where is the light source located on a compounds microscope?

Back 96

at the base

Front 97

what kind of focusing knobs are on the compounds microscope?

Back 97

two, a fine and a course one

Front 98

what do you do to focus an image on a compound microscope?

Back 98

move either stage (specimen/object) or nosepiece to focus image

Front 99

what does the substage condensor do on the compound microscope?

Back 99

it focuses cone of light on slide

Front 100

how many objective lenses does the nosepiece hold on the compound microscope?

Back 100

3-5 objective lenses

Front 101

what two lenses seperate object from the eye in a compound microscope?

Back 101

-objective lense (placed next to object) and
-ocular lense (located next to eye)

Front 102

what is magnification determined by in compound microscope(CM)?

Back 102

by multiplying magnification of objective and ocular lenses

objective usually 4x, 10x, 20x, 40x or 100x
oculars are usually 10x, sometimes 15x

Front 103

what is the upper limit on CM?

Back 103

1500,
limit is due to a property of lens called the resolution

Front 104

Resolving power is a function of

Back 104

-light wavelength and
-objective lens Numerical Aperture (NA)

Front 105

how does a lense bend light?

Back 105

when light ray passes through one substance e.g, air into another, e.g. glass, the ray slows as it enters the glass and bends towards the normal. This bending is REFRACTION. As ray leaves flass and enters air, it accelerates ad bends away from the normal

Front 106

What is a measure of ability of medium (air, water, glass) to bend light rays?

Back 106

Refractive index

Front 107

a lens acts as a series of prisms, bends or focuses light on a point called a

Back 107

focal point

Front 108

what is the distance between the centre of the lens and focal point?

Back 108

focal length

Front 109

how does a microscope lens effectively decrease focal length?

Back 109

the shorter the effective focal length, the larger the object appears, a microscope magnifies an image by decreasing the focal length

Front 110

the minimum (d) between two objects that can be distinguished as separate can be determined from what formula?

Back 110

d = 0.5 x wavelength /refractory index x sin (NA)


wavelength is also known as resolution

Front 111

what does NA stand for?

Back 111

Numerical aperture

Front 112

the shorter the effective focal length, the

Back 112

larger the object appears

Front 113

the longer the focal length, the

Back 113

smaller the object appears

Front 114

a light microscope cannot be used with wavelengths smaller than

Back 114

500nm

Front 115

the human eye cannot see wavelengths shorter than

Back 115

violet light

Front 116

at 500nm (0.5micro meters) resolution increases only by

Back 116

increasing numerical aperture (NA)

Front 117

the NA for air is

Back 117

0.87

Front 118

how do you increase resolution (wavelength)?

Back 118

must increase numerical aperture (NA)

Front 119

when you immerse an object in oil (immersion oil), effectively it changes the numerical aperture (NA) to

Back 119

1.5

Front 120

what is the numerical aperture for air?

Back 120

0.87

Front 121

what is the numerical aperture for oil immersion?

Back 121

1.5

Front 122

how does immersion oil increase numerical aperture (NA)?

Back 122

The numerical aperture is a measure of the cone of light that can be gathered by the objective and therefore a decrease in light that is diffracted will increase the light that is gathered by the objective.

In light microscopy, oil immersion is a technique used to increase the resolution of a microscope. This is achieved by immersing both the objective lens and the specimen in a transparent oil of high refractive index, thereby increasing the numerical aperture of the objective lens.

Front 123

what is the RI (refractory Index) of air?

Back 123

1.0

Front 124

what is the numerical aperture of air?

Back 124

0.87

Front 125

maximum resolution occurs if use shortest possible wavelength (500nm = 0.5 um) the maximum numerical aperture is

Back 125

1.5

Front 126

for maximum resolution, light must just cover the

Back 126

entire surface of lens

Front 127

if one moves the lens clloser to the light source, the light rays do not strike the

Back 127

entire lens

Front 128

the distance of the lens from the object, and so resolution is limited by the

Back 128

angle of the cone of light

Front 129

what is 1/2 the angle of the cone of light that enters from the specimen?

Back 129

the aperture angle, is 1/2 the angle of the cone of light that enters from the specimen

Front 130

the angle of the cone of light entering the objective, is also called the

Back 130

aperture angle

Front 131

to increase the aperture angle of the cone of light, you must

Back 131

increase refractoy index

Front 132

how do you increase refractory index (RI)?

Back 132

immersion oil

Front 133

immersion oil has a maximum refractive index of 1.5 and therefore increases aperture angle to

Back 133

90 degrees

Front 134

oil (immersion oil) allows the lens to be moved closer to the sample thereby doing what to the focal length and magnification?

Back 134

oil decreases focal length and increases magnification

Front 135

a greater refractive index results in

Back 135

a greater angle over which light is spread before entering the lens

Front 136

without immersion oil, what happens to the light in a microscope?

Back 136

most of the light is refracted and lost

Front 137

maximum resolution occurs if you use

Back 137

the shortest possible wavelength of light (500nm =0.5 um) and
the maximum aperture angle value =1 (sin90 =1) with a
refractive index of 1.5

Front 138

when maximum resolution is applied with immersion oil, what magnification can be seen?

Back 138

we can see a speck of ~0.2 um diameter

Front 139

useful magnification limit is what? and what can it be increased to?

Back 139

limit is 1000x but can be increased to about 10000x

Front 140

a small size and poor contrast with surrounding medium nmakes microorganisms hard to see under the light microscope, therefore what measures are applied?

Back 140

fixing and staining

Front 141

what is the point of fixing ans staining

Back 141

-to increase visibility
-accentuate specific morphological features
-preserve specimens for future study

Front 142

what is the definition of fixation?

Back 142

to preserve and fix in position internal and external structures

Front 143

how many steps are involved in fixation?

Back 143

1-heat fixation
2-chemical fixation

Front 144

what is heat fixation?

Back 144

to gently flame-heat an air-dried film of bacteria (doesn't preserve internal structure)

Front 145

what is chemical fixation?

Back 145

it is required to protect internal structure (chemicals penetrate cells and react with cellular components to make them insoluble and immobilize them)

chemicals used include: ethanol, acetic acid, formaldehyde, glutaraldehyde

Front 146

dyes used to stain cells have what two common features?

Back 146

-they have a chromophore group (gives dye its color)
-they bind by ionic, covalent or hydrophobic binding


dye stains cells,increases contrast with background

Front 147

positive staining includes what three dyes/stains?

Back 147

-Basic dyes (cationic+)
-acidic dyes (anionic-)
-fat soluble stains (lipophilic not ionic)

Front 148

what kind of dye has the following characteristics?
-have positively charged groups
-bind to negatively charged materials
-bacterial surfaces are usually verily charged, so these are good simple dyes for staining bugs
-they include methylene blue, crystal violet, basic fuchsin, safranin, malachite green dye

Back 148

Cationic (Basic dye)

Front 149

what dye has the following characteristics?
-have negatively charged groups
-bind to positively charged materials
-dyes include congo red, acidic fuchsin, and eosin colors

Back 149

Anionic (acidic dye)

Front 150

the pH can alter staining effectiveness of both types of dyes (cationic and anionic) because the nature and degree of charge on what changes with pH?

Back 150

the nature and degree of charge on the cell component changes with pH

Front 151

which dye works best at high pH (base) where many molecules carry a negative (-) charge

Back 151

Cationic (basic dye)

Front 152

which dyes work best at low pH (acid) where many molecules carry a positive charge

Back 152

Anionic (acidic dye)

Front 153

which stain dissolves in and combines with lipid inclusions, and will not dissolve in aqueous portions of cell?

Back 153

Fat soluble stains (lipophilic not ionic)

Front 154

in what sort of staining method are cells left unstained, with dark background,
-use opaque material, spread in thin later and must not dry out,
-it is used for showing the presence of capsules around cells (e.g. India ink)

Back 154

negative staining

Front 155

not all bacteria or bacterial components are stained equally, this is the basis for

Back 155

differential staining

Front 156

differential staining includes:

Back 156

-endospore stain
-acid fast staining
-the Gram stain

Front 157

what species form endospores?

Back 157

Bacillus and Clostridium

Front 158

out of all the three differential staining methods, which one is the most widely used?

Back 158

the Gram stain

Front 159

why is the Gram stain the most widely used of all stains?

Back 159

because it chemically distinguishes two kinds of cell wall, and divides bacteria into two classes (gram positive and Gram negative)

Front 160

what color stain is gram positive?

Back 160

purple

Front 161

what color stain is gram negative?

Back 161

red

Front 162

what is the 4 mechanisms behind a gram stain reactions

Back 162

- Crystal violet (CV)
-Iodine solution (I)
-Alcahole
-Safarin

Front 163

what is the reaction of the stain "crystal violet" (CV)?

Back 163

all cells stain violet

Front 164

what is the reaction of the iodine solution (I)?

Back 164

water insoluble CV-I complex forms within cells. cells remain violet. Iodine functions as mordant: increases interaction between cell and dye

Front 165

what is the reaction of staining with alcahol?

Back 165

in gram positive bacteria: cell wall is dehydrated pores shrink, CV-I complex cant pass out of cells, cells thus remain violet

in gram negative bacteria: Lipid leached from cell wall increasing porosity, CV-I escapes from cell, cell becomes colourless

Front 166

what is the reaction of the stain Safranin?

Back 166

Gram positive bacteria is not affected and remains violet but in gram negative bacteria, it takes up the stain ad becomes pink or red

Front 167

is E coli gram negative or positive bacteria?

Back 167

Gram negative

Front 168

Cocci in Red Blood Cells is Gram negative or positive?

Back 168

gram positive

Front 169

living, unstained cells can be observed by

Back 169

changing the way they are illuminated under the microscope

Front 170

in a darkfield microscope, how does the light reach the specimen?

Back 170

light reachest the specimen from the siodes only and detects reflected lighjt, the cells appear bright against a dark background

Front 171

what is the darkfield microscope good for?

Back 171

it is good for looking at small objects often visible by other means

Front 172

in the darkfield microscope, what does the dark field stop do?

Back 172

the hollow cone of light produced by the dark field stop ensures that the only light entering the objective is reflected off, or refracted through the specimen

Front 173

in phase contrast microscopy, unpigmented cells are

Back 173

hard to see, the PC microscope amplifies this difference and convert is to difference in contrast

cells and internal structures appear dark against a bright background in phase contrast microscope

Front 174

what microscopes can be used for living cells in wet mounts?

Back 174

Dark field microscope and
phase contrast microscope

Front 175

what microscope is based on the emission of light by the observed object

Back 175

Fluorescence Microscope

Front 176

what kind of dye when illuminated by short wavelength lgiht, emit longer wavelength (fluorescent) light?

Back 176

Fluorescent dyes

Front 177

what range of colors are in fluorescent dyes?

Back 177

acridine orange, and ethidium bromide

Front 178

what kind of light is used in fluorescence microscope?

Back 178

UV light, Halogen light source (near ultraviolet) produces intense beam

Front 179

in a fluorescent microscope, incident illumination is from

Back 179

above or below

Front 180

how many types of fluorescent microscopes are there?

Back 180

2 types

Front 181

what kind of microscope has a barrier to protect the eye from UV light?

Back 181

fluorescent microscope

Front 182

what is the fluorescent microscope useful for?

Back 182

tagging proteins, DNA etc

it is an excellent diagnosis tool

Front 183

what is the problem associated with the Transmission Electron Microscope (TEM)

Back 183

-It's useful magnification is limited by wavelength of illuminator
-resolution decreases with decrease in wavelength
-human eye cannot see wavelength <500nm
100,000 times shorter than wavelength of violet light

Front 184

transmission electron microscope (TEM) beams electrons having wavelength of

Back 184

0.005nm

Front 185

the theoretical resolution of the TEM is

Back 185

2A, twice the diameter of a Hydrogen (H) atom

Front 186

the TEM uses electromagnetic lenses to

Back 186

bend electron beam for focusing

Front 187

where speciemtns must be dehydrated and embedded in plastic before being cut into very thin (60nm) sections, this is called

Back 187

thin sectioning

Front 188

complete dehydration of specimens is essential since

Back 188

many plastics are not water soluble

Front 189

thin sections of specimens are stained before being view under the

Back 189

Transmission Electron Microscope (TEM)

Front 190

negative staining is used in what kind of microscope?

Back 190

Transmission Electron Microscope (TEM)

Front 191

what kind of miroscope uses an illuminated laser beam?

Back 191

Confocal Scanning Microscope (CSM)

Front 192

what does the laser beam do in the CS microscope?

Back 192

the beam focuses on one point of a specimen using an objective lens mounted between condenser lenses and specimen, and then mirrors are used to pass (scan) the beam across the specimen in X and Y directions,
alternatively, the beam focuses at particular plane of preparation

Front 193

a confocal scanning microscope can produce what kind of image?

Back 193

images from different layers can be stores and digitally overlaid to construct 3D image of entire specimen

Front 194

intact cells or cell components can be viewd directly using a

Back 194

scanning electron microscope (SEM)

Front 195

what does the SEM do?

Back 195

it scans electrons across a specimen and collects secondary electrons discharged from the specimens atoms, which is then reflected radiation observed on a TV screen

Front 196

in a Scanning Electron Microscope, what is the Critical point drying method?

Back 196

water is removed as vapour to minimise structural damage to specimen, the speciment is then coated with gold or palladium to reflect electrons

Front 197

which microscope has a greater depth of field, the SEM or the TEM?

Back 197

the SEM

Front 198

what objective lense do you view your newly stained slide with?

Back 198

after placing a drop of oil on the slide, examine with a 100x objective lense

Front 199

what do stains improve?

Back 199

the contrast between cells and their background

Front 200

what are basic dyes? why are they useful? (2.1 and 2.2)

Back 200

microscopes are essential for studying microorganisms. Bright field microscopy, the most common form of microscopy, employs a microscope with a series of lenses to magnify and resolve the image

Front 201

what is the main difference between a phase contrast microscope and a light microscope? (2.2)

Back 201

an inherent limitation of bright field microscopy is the lack of contrast between cells and their surroundings. this problem can be overcome by the use of stains or by alternative forms of light microscopy such as phase contrast or dark field

Front 202

what is the major advantage of electron microscopes over light microscopes? what type of electron microscope would be use dot view the three dimensional features of a cell? (2.4)

Back 202

Electron microscopes have far greater resolving power than do light microscopes, the limits or resolution being about 0.2nm.the two major forms of electron microscopy are transmission used mainly to observe internal cell structure, and scanning, used to examine the surface of specimens

Front 203

which domains of life have a prokaryotic cell structure? Is prokaryotic cell structure a predictor of phylogenetic status (2.5)

Back 203

all microbial cells share certain basic structures, such as their cytoplasmic membrane and ribosomes, most bacterial cells have a cell wall. two structural patterns of cells are recognized, the prokaryote and the eukaryote. viruses are not cells and depend on cells for their replication

Front 204

how do you determine the evolutionary relationship between organisms? (2.7)

Back 204

comparative rRNA gene sequencing has defined three domains of life: Bacteria, Archaea, and Eukarya. Molecular sequence comparisons have shown that the organelles of Eukarya were originally Bacteria and have spawned new tools for microbial ecology and clinical microbiology, which explains the word endosymbiosis

Front 205

what are one of two known domains of prokaryotes, compared with Bacteria?

Back 205

Archaea

Front 206

what is an organisms able to grow with carbond dioxide as its sole carbon source?

Back 206

an autotroph

Front 207

what is one of two known domains of prokaryotes,compared with Archaea?

Back 207

Bacteria

Front 208

what is a rigid layer present outside the cytoplasmic membrane, confers structural strength to the cell and protection from osmotic lysis?

Back 208

cell wall

Front 209

what is an organism that obtains its energy from the oxidation of inorganic compounds?

Back 209

Chemolithotroph

Front 210

what s an organism that obtains its energy from the oxidation of organic compounds?

Back 210

Chemoorganotroph

Front 211

what is a genetic element containing genes essential to cell function?

Back 211

chromosome

Front 212

what is a prokaryotic oxygenic phototrophs?

Back 212

Cyanobacteria

Front 213

what is the aqueous internal portion of a cell, bounded by the cytoplasmic membrane?

Back 213

Cytoplasm

Front 214

what is the cells permeability barrier to the environment, encloses the cytoplasm?

Back 214

Cytoplasmic membrane

Front 215

what is the highest level of biological classification?

Back 215

Domain

Front 216

what is the theory that mitochondria and chloroplasts orgiinated from bacteria?

Back 216

Endosymbiosis

Front 217

what is the domain of life that includes all eukaryotic cells?

Back 217

Eukarya

Front 218

what is a cell having a membrane enclosed nucleus and usually other membrane enclosed organelles?

Back 218

Eukaryote

Front 219

what is a change in a line of descent over time leading to new species or varieties within a species?

Back 219

evolutionextremophiles

Front 220

what is an organisms that grown optimally under one or more environmental extremes?what is a differential staining technique in which bacterial cells stain either pink or (gram negative) or purple (gram positive) depending upon their structural makeup?

Back 220

gram stain

Front 221

what is an organism that requires organic carbon as its carbon source?

Back 221

Heterotroph

Front 222

what is the aggregated mass of DNA that constitutes the chromosome of cells of Bacteria and Archaea?

Back 222

Nucleoid

Front 223

what is a membnrane enclosed strucutre that contains the chromosomes in euckaryotic cells?

Back 223

nucleus

Front 224

what is a membrane enclosed strucutre, such as a mitochondria or chlorioplast, present in the cytoplasm of eukaryotic cells?

Back 224

organelle

Front 225

what is an organism that obtains its energy from light?

Back 225

phototroph

Front 226

what is the evolutionary relationships between organisms?

Back 226

Phylogeny

Front 227

what is an extra chromosomal genetic element nonessential for growth?

Back 227

Plasmid

Front 228

a cell that lacks a membrane enclosed nucleus and other organelles is called a

Back 228

prokaryote

Front 229

a large phyluum of bacteria that includes many of the common gram negative bacteria such as Escherichia coli is called

Back 229

proteobacteria

Front 230

protist include

Back 230

algae and protozoa

Front 231

in microscopy, the ability to distnguish two objects as distinct and seperate under the miroscope is known as

Back 231

resolution

Front 232

a cytoplasmic particle that functions in protein synthesis is called a

Back 232

Ribosome

Front 233

what is a genetic element that contains either a DNa or an RNA genome, has an extracellular form (virion) and depends on a host cell for replication?

Back 233

a virus

Front 234

The ability to distinguish two adjacent objects as distinct and separate is known as

Back 234

resolution.

Front 235

Why are dyes used to stain specimens prior to microscopy?

Back 235

To increase resolution

Front 236

One type of light microscopy that can improve contrast without the use of staining is:

Back 236

dark-field microscopy.

Front 237

The type of microscopy that can be used to view individual cells in a biofilm is known as:

Back 237

confocal laser scanning microscopy.

Front 238

What kinds of cells do not have a cell wall?

Back 238

Animal cells

Front 239

The segment of DNA that encodes a protein or an RNA molecule is known as a(n):

Back 239

gene.

Front 240

An example of a function that genes on a plasmid could encode is:

Back 240

antibiotic resistance.

Front 241

An example of an environment that may contain extremophiles is:

Back 241

a salt lake.

Front 242

Oxygenic photosynthesis is carried out by:

Back 242

cyanobacteria.

Front 243

Bacteria and Archaea are both prokaryotic groups. What technique can distinguish between these two groups?

Back 243

rDNA sequencing

Front 244

Following the Gram stain procedure, gram-positive bacteria appear:

Back 244

purple.

Front 245

What type of microscope would you use if you are viewing a light specimen on a contrasting background?

Back 245

Dark-field microscope

Front 246

Which type of microscopy would NOT produce three-dimensional images of microscopic specimens?

Back 246

Phase contrast microscopy

Front 247

The resolving power of an electron microscope is much greater than that of the light microscope because:

Back 247

the wavelength of electrons is much shorter than the wavelength of visible light used in a light microscope.

Front 248

In addition to being the boundary between the external environment and the inside of the cell, in prokaryotes the cytoplasmic membrane also functions in which of the following?

Back 248

Energy conservation reactions

Front 249

Prokaryotes are generally haploid, whereas the majority of eukaryotes are:

Back 249

diploid.

Front 250

The molecule most commonly used to determine evolutionary relationships between organisms is:

Back 250

rRNA gene

Front 251

Primary producers are classified as:

Back 251

autotrophs

Front 252

The largest phylum in the domain Bacteria is:

Back 252

proteobacteria

Front 253

The domain Archaea contains two phyla known as:

Back 253

Crenarcheota and Euryarcheota.

Front 254

Microorganisms that have been successfully cultured in the laboratory represent only a small fraction of the diversity of microorganisms on Earth. We know this because of:

Back 254

data obtained using rRNA gene analyses on environmental samples.

Front 255

A phylotype is:

Back 255

an uncultivated microorganism known only by its rDNA sequence

Front 256

The groups representing the microbial Eukarya are:

Back 256

algae, protozoa, fungi, and slime molds.

Front 257

what are the 7 different types of bacterial shape, size and structure

Back 257

-Morphology
-Cocus
-Bacillus
-Spirillum
-Spirochaete
-Budding and appendages bacteria
-Filamentous

Front 258

morphology describes the

Back 258

shape of the cell

Front 259

coccus desribes a

Back 259

spherical or ovoid pl
:cpcci

Front 260

Bacillus describes a

Back 260

rod shaped pl: bacilli

Front 261

Spirillum describes a

Back 261

slight spiral curve

Front 262

a spirochaete describes an

Back 262

extensive spiralling of the cell

Front 263

Budding and appendaged bacteria describes

Back 263

cells with stalks or filament like hyphae attached

Front 264

Filamentous describes

Back 264

extremely elongated cells

Front 265

at division, cells may remain

Back 265

attached to one another

Front 266

during divisions cell that divides along the same axis forms

Back 266

-short (diplococcus, Neisseria)
-or long chains (streptococcus)

Front 267

during division cells divide along two axes at right angles form

Back 267

sheets (tetrad)

Front 268

as cells divide along three exes they form

Back 268

cube shaped packets

Front 269

when cells form clupms in division such as staphyloccocus, there is no specific

Back 269

pattern to orientation of division on any axis

Front 270

Bacilli are also known as

Back 270

rods

Front 271

if Bacilli (rods) divide only in one plane, they may form

Back 271

chains (streptobacilli)

Front 272

what kind of bacteria divide only in one plane and usually seperate immediately?

Back 272

Spiral Bacteria

Front 273

what is the size of a bacillus megaterium?

Back 273

1.5 x 4um

Front 274

what is the size of Escherichia coli?

Back 274

1x3 um

Front 275

what is the size of a streptococcus pneumoniae?

Back 275

0.8 um diameter

Front 276

what is the size of a haemophilus influenzae?

Back 276

0.25 x 1.2 um

Front 277

what is the size of a Oscillatoria (a cynobacterium)?

Back 277

8 x 50 um

the largest bacteria

Front 278

what is the range for cell size?

Back 278

0.1 -50 um in diameter, and
1 to 500 um in length

Front 279

the small size of most cells effects their

Back 279

biological properties

Front 280

the rate at which nutrients or waste enter or leave a cell influences its

Back 280

metabolic rates and growth rates

Front 281

Rate is inversely proportional to

Back 281

cell size

Front 282

Rate is

Back 282

function of available Surface area relative to Volume

Front 283

the greater Surface area relative to volume the

Back 283

faster transport occurs

Front 284

the surface area and volume ratio of a cell does not show the size of the cell, but the

Back 284

surface area alone does

Front 285

why do cells have a surface area/volume?

Back 285

this all leads to more efficient intake of nutrients and export of wastes --> rapid growth rate --> larg populations

Front 286

you can break open cells using such chemicals as

Back 286

ensymes (lysozyme) or sonication

Front 287

what is sonication?

Back 287

the use of high frequency sound waves to vibrate cells until they break

centrifusion is then used to seperate components

Front 288

what are the different types of centrifusion techniques?

Back 288

-velocity centrifusion and
-Density gradient centrifusion

Front 289

what centrifusion technique uses time vs centrifugal force?

Back 289

Velocity centrifusion

Front 290

what centrifusion technique uses components sedimented through gradient of sugar or salt concentration?

Back 290

density gradient centrifugation

Front 291

during desncity gradient centrifusion cells seperate according to

Back 291

-weight

Front 292

what happens during velocity centrifugation: time vs. centrifugal force?

Back 292

-denser structures sediment in quick, low speed spins
-at high speed, for longer time, less dense structures sediment
-supernatant contains enzymes, amino acids, nucleotides, dissolve nutrients etc

Front 293

during desnsity gradient centrifugarion where components sedimented through gradient of sugar or salt concentration, what happens to the concetration and desnisy?

Back 293

the lowest concetration and lowest density say at the top, and the greatest concetration and greatest desnsity stay at the bottom

During centrifugation, cellular gractions sediment to point where their desnity matchest density of gradient

Front 294

cellular structure include two kinds of structures what are they?

Back 294

-gross structure and
-fine structure

Front 295

what structure includes features associated with an outer surface of bacterium?

Back 295

Gross structure

Front 296

what structure usually refers to internal cell contents and detailed cell wall structure?

Back 296

Fine structure

Front 297

what is the function of the prokaryotic structure: Plasma membrane?

Back 297

Selectively permeable barrier, mechanical boundary of the cell, nutrient and waste transport, location of many metabolic processes (Respiration, photosynthesis), deterction of environmental cues for chemotaxis

Front 298

what is the function of the prokaryotic structure: Gas vacoule?

Back 298

boutancy for floating in aquatic environments

Front 299

what is the function of the prokaryotic structure: Ribosomes

Back 299

protein synthesis

Front 300

what is the function of the prokaryotic structure: Inclusion bodies?

Back 300

Storage of carbon, phosphate, and other substances

Front 301

what is the function of the prokaryotic structure: nucleoid?

Back 301

localization of genetic material (DNA)

Front 302

what is the function of the prokaryotic structure: Periplasmic space

Back 302

contains hydrolytic enzymes and binding proteins for nutrient processing and uptake

Front 303

what is the function of the prokaryotic structure: Cell wall

Back 303

gives bacteria shape and protection from lysis in dilute solutions

Front 304

what is the function of the prokaryotic structure: Capsules and slime laters

Back 304

resistance to phagocytocis, adgerence to surfaces

Front 305

what is the function of the prokaryotic structure: Fimbrine and pili

Back 305

attachment to surfaces, bacterial mating

Front 306

what is the function of the prokaryotic structure: Flagella

Back 306

movement

Front 307

what is the function of the prokaryotic structure: Endospore

Back 307

survival under harsh environmental conditions

Front 308

the cell membrane (cytoplasmic, plasma) is how thick?

Back 308

8nm thick bilayer

Front 309

the cell membrane (cytoplasmic, plasma) is visible under the

Back 309

TEM (Transmission Electron Microscope)

Front 310

the cell membrane (cytoplasmic, plasma) seperates

Back 310

internal cell constituents from the environment

Front 311

the cell membrane (cytoplasmic, plasma) is permeable to various substances but this is

Back 311

selective, selectively permeable

Front 312

the cell membrane (cytoplasmic, plasma) restricts the

Back 312

passive movement (diffusion) of dissolved solutes

Front 313

most molecules move across the plasma membrane by

Back 313

specific transport systems

Front 314

the movement of molecules across the Plasma Membrane either by passive or active transport, allows the cell to

Back 314

concentrate metabolites and excrete wastes

Front 315

the plasma membrane is

Back 315

selectively permeable

Front 316

the plasma membrane is a barrier to

Back 316

penetrate and agent of transport

Front 317

the plasma membrane serves as the site of

Back 317

proton motive force (PMF) generation,
cell wall synthesis,
chromosome attachement

Front 318

the plasma membrane consist of a phospholipid bilater with associated

Back 318

proteins (Varies from cell to cell)

Front 319

prokaryotes contain what kind of protein within their plasma membrane?

Back 319

Prokaryotes contain hopanoid within plasma membrane

Front 320

Eukaryotes contain what kind of protein within their plasma membrane?

Back 320

eukaryotes contain cholesterol within their plasma membrane

Front 321

phospholipids have a hydrophilic

Back 321

head
(glycero-phosphate)

Front 322

phospholipids contain a hydrophobic

Back 322

tail (fatty acid)

Front 323

phospholipids are

Back 323

amphipathic

Front 324

how are phospholipids amphipathic?

Back 324

they aggregate with tails pointing inwards (creating hydrophobic compartment in middle of bilayer) and heads pointing outward in contact with the aqueous environment

Front 325

plasma membranes are nbot rigid but in a

Back 325

fluid state (Especially lpids)

Fluid mosaic

Front 326

most membrane lipids and some proteins can drift

Back 326

laterally within the membrane

Front 327

due to physical contrasint molecules cannot easily

Back 327

flip from one side of the membrane to the other

Front 328

membranes are held together by

Back 328

inter molecular forces:
H bonds and hydrophobic interactions, also sterol like compounds (Cholesterol)

Front 329

sterols are thought to be important in

Back 329

maintaining the stability of the fluid dynamics of the plasma membrane

Front 330

animals have cholesterol or hopanoids?

Back 330

cholesterol

Front 331

Bacteria have cholesterol or hopanoids?

Back 331

Bacteria have sterol like hopanoids (made from steroids)

Front 332

what is the role of cholesterol and hopanoid sterols in the plasma membranes?

Back 332

they lead to membrane stability while maintaining fluidity

Front 333

The E coli plasma membrane has how many different phospholipids and proteins?

Back 333

E coli has 7 different phospholipids and
200 different proteins

Front 334

many what are integral pr transmembrane proteins?

Back 334

proteins

Front 335

transmembrane proteins have adefined

Back 335

orientation, with the inside being different to the outside

Front 336

many transmembrane proteins are involved in

Back 336

transport in and out of cell (form proteinaceous pores or pumps)

Front 337

in the cell membrane, some substances are

Back 337

transportes and some are exluded

Front 338

molesulces can move across the plasma membrane in

Back 338

different ways

Front 339

lipid soluble (hydrophobic) compounds can

Back 339

easily dissolve into and cross biological plasma membrane (diffusion)

Front 340

small non charges water soluble compounds can diffuse through the

Back 340

aqueous channels in proteins imbedded in plasma membrane

Front 341

large hydrophilic compounds cross the membrane how?

Back 341

they are transported across the membrane via energy dependent and energy non dependent mechanisms

Front 342

describe diffusion of molecules or atoms?

Back 342

molecules or atoms move from areas of high concentration to areas of low concentration (down a concentration gradient)

Front 343

diffusion of a suibstance across a biological memrbane is called

Back 343

passive transport

Front 344

passive transport do not require work and continues until a

Back 344

dynamic equilibrium is reached

Front 345

during diffusion the substance continues to move across the membrane but there is no

Back 345

net directional movement

Front 346

the rate of diffusion is regulated by the

Back 346

permeability of the membrane for the substance
(water=100, glycerol =0.1; tryptophan = 0.001; Cl =0.000001; Na=0.000000001)

Front 347

the cell interior is an aqueous solution of

Back 347

salts, sugars, amino acids, vitamins, proteins (enzymes) etc

Front 348

the Hydrophobic natura of membrane makes it a

Back 348

tight barrier

Front 349

during membrane transport process, small hydrophobic molecules may pass through by

Back 349

diffusion

Front 350

how does water pass through plasma memrbane

Back 350

water is uncharged and small and passes through the phospholipids easily

Front 351

charged and hydrophilic molecules do not penetrate membrane (organic acids, sugars, aas inorganic salts) and must

Back 351

be carried by transport proteins

Front 352

transport proteins can concentrate up to

Back 352

1000x

Front 353

transport is needed to achieve right

Back 353

cellular conncentration

Front 354

for diffusion, rate of uptake and cellular level depend on

Back 354

external conncentration, the external concentration us usually too low

Front 355

what is the mechanistic soolution to the fact that externall concentration is usually too low?

Back 355

Carrier mediated transport mechanisms are the cells solution to this

Front 356

facilitated diffusion involves

Back 356

facilitator proteins and requires no energy

Front 357

what are carriers, that pick ip molecules on one side of the membrane and transport to the other side?

Back 357

facilitator proteins

Front 358

the affinity of carrier proteins for substrate is the

Back 358

same on both sides

Front 359

what will a substrate do if the concentration is higher outside the cell than inside the cell?

Back 359

the substrate will move in, and continues until the concentration inside the cell is the same as outside the cell

Front 360

carrier mediated transport includes both

Back 360

facilitated diffusion and active transpoty

Front 361

what does carrier mediated transport allow?

Back 361

it allows cells to accumilate solutes agaist a concentration gradient

Front 362

what is it called when all carrier molecules in contact with sunstrate, have a rate of uptake that becomes maximal?

Back 362

it is called a Saturated effect

Front 363

carrier mediated transport is highly

Back 363

specific,
cell regulated

Front 364

carrier proteins may react with a single

Back 364

molecule or single chemical class of molecules

Front 365

facilitated diffusion seems useful only if there is a

Back 365

high concentration of substrate outside the cell

Front 366

some bacteria use a trick to move molecules against a concetration gradient by

Back 366

facilitated diffusion, by modifying the molecule as soon as it enters the cell

Front 367

carrier proteins dont recognise a

Back 367

phosphorylated glycerol and see the intracellular glycerol concentration as being low

Front 368

what are the three classes of energy requiring transporting systems in the cell?

Back 368

-Active transport (symporter)
-Group translocation (phosphotransferase system of E coli)
-ABC system

Front 369

what kind of energy does the active transport (symporter) transport?

Back 369

pmf (proton motive force)

Front 370

what sort of energy does the "Group translocation " (phosphotransferase system of E coli) transport?

Back 370

P)4 (phosphate)

Front 371

what sort of energy does the "ABC system" transport?

Back 371

ATP (adenosine tri phosphate)

Front 372

what kind of transport uses energy to transport a substance against its concentration gradient?

Back 372

active transport

Front 373

does the substance being transported via active transport modify during the transport?

Back 373

the substance does not get chemically modified during transport

Front 374

what kind of channel does the substance get transported through via active transport?

Back 374

the substance moves through a channel formed by protein subunits

Front 375

what are the 3 types of Active transport (AT) proteins (permeases)

Back 375

-uniporter
-symporter
-antiporter

Front 376

which permease (AT) protein transports one substance at a time from one side of the membrne to other?

Back 376

uniporter

Front 377

which permease (AT) protein carries 2 substances (one is often H) across membrane in same direction?

Back 377

symporter

Front 378

which permease (AT) carries one substance in one direction, and the second in the opposite direction?

Back 378

antiporter

Front 379

the "energy" of the active transport is provided by

Back 379

PMF (proton motive force)

Front 380

PMF energy is due to

Back 380

the seperated of proteons from hydroxyl ions across the membrane, where protons exported out of the cell causes higher concentration outsid ethe cell and an excess of positive charge is on the outside of the membrane

Front 381

hydroxyl ions have a negative charge, so an excess of negative charge inside the membrane favours

Back 381

movement of protons or other positive molecules back in from the region of postiive charge to region of negative charge

Front 382

what ion is transported into a cell by uniporters due to proton motive force?

Back 382

K+ (potassium ion)

Front 383

charge seperation is a form of

Back 383

metabolic energy

Front 384

what charged molecules are brought into the cell by symporters?

Back 384

negative charged (-)

Front 385

why do symporters bring in negatively charged molecules?

Back 385

because the symporters bind proteons which neutralise the negative charge on cotransported molecules

Front 386

symporters allow neagtively charged molecules to be

Back 386

moved in an area of negative charge

Front 387

lactose is a negative charege molecule and is berough into the cell

Back 387

through the lac permease which is a symporter

Front 388

active transport uses both

Back 388

proton motive force and
Na+ sodium grandients

Front 389

in E coli, the sodium (Na+) gradient is set upo b

Back 389

proton antiport, that drives the uptake of sugars and amino acids by a symport mechanism

Front 390

group translocation is found only in

Back 390

prokaryotes

Front 391

during what occasion is transported substances chemically altered during passage (cf.AT) by the addition of a phosphate?

Back 391

during Group translocation that occurs only in prokaryotes

Front 392

what molecules are transported in Group translocation?

Back 392

Glucose, fructose and mannose

Front 393

where does the erergy for transport come from in group translocation?

Back 393

it comes from high energy phosphate compounds (Phosphoenolpyruvate PEP) and is released when the phosphate is attached to the sugar

Front 394

binding protein trasnport is also called

Back 394

ABC transport

Front 395

ABC transport is found in both

Back 395

gram positive and gram negative bacteria

Front 396

in gram negative, it involves specific molbile binding proteins in the

Back 396

periplasmic space (the area between cytoplasmic membrane anchored to external surface of cytoplasmic membrane

Front 397

in gram positive, it involves what kind of binding proteins that is cnchored to the external surface of cytoplasmic membrane

Back 397

specific (solute) binding proteins

Front 398

specific binding proteins (SBP) transfer molecules to

Back 398

active transport proteins in cytoplasmic membrane

Front 399

a third binding protein in ABC transport which has no binding sites at the membrnae cell interior boundary enables energy to be provided by

Back 399

ATP hydrolysis

Front 400

E coli trasnports several sugars such as arabinose, maltose, galactose and ribose and amino acids glutamate, histidine, lecucine by what kind of transport?

Back 400

by ABC transport (ATP binding cassette) trasnsporters

Front 401

gram negative bacteria like E coli need to pass a substance through the outer membrane before

Back 401

ABC transport- through porins

Front 402

What disease comes from an inactivation of an ABC chloride transporter in the lungs?

Back 402

cystic fibrosis

Front 403

E coli has how many transport systems for galactose?"

Back 403

at least 5

Front 404

E coli has how many transport systems each for glutamate and lecuine

Back 404

three

Front 405

e coli has how many potassium (K+) transport complexes?

Back 405

two

Front 406

E coli's various mechanisms differ in

Back 406

energy source, affinity for substrate and nature of their regulation

good in a changing environment

Front 407

ionphores desctroy

Back 407

the selective permeability of membranes

Front 408

how do ionphores do what they do to destroy permeability?

Back 408

they are small hydrophobic molecules that dissolve in lipid bilayers (hydrophobic periphery)

Front 409

what do ionphores allow?

Back 409

they allow the passive diffusion of charged molecules into and out of cells

Front 410

what makes membranes leaky and offset essential concentration gradients?

Back 410

ionphores

Front 411

what is beneath any extracellular material and external to the plasma membrnae?

Back 411

the cell wall

Front 412

what has a rigid structure and cell shape?

Back 412

cell wall

Front 413

how thick is the cell wall

Back 413

10-25 nm thick

Front 414

what percent does the cell wall constitute of the drty weight of the cell?

Back 414

it constitutes 10-40% dry weight of organism

Front 415

how is the cell wall is essential to the organisms that produced them

Back 415

-cell wall protects internal components from mechanical damage
-determines cell shape
-acts as a molecular sieve
-cell wall prevents ozmotic lysis

Front 416

how does the cell wall determine the cell shape?

Back 416

the isolated protoplast is spherical, regardless of shape of original cell

Front 417

how does the cell wall act as a molecular sieve?

Back 417

it has a permeability barrier that excludes certain molecules, and
actively regulated transport of ions and other molecules

Front 418

high concentration of solutes in a cell leads to

Back 418

considerable turgor pressure

Front 419

turgor pressure is due to

Back 419

water entering a cell via osmosis

Front 420

if a cell loses its cell wall it is called a

Back 420

porotoplast

Front 421

if a protoplast is suspended in medium that is more dilute that its cytoplasm,

Back 421

water enters via osmosis, the turgot pressure causes the cell to swell and burst (osmotic lysis)

Front 422

what is movement of molecules from region of high concentration to region of low concentration?

Back 422

diffusion

Front 423

when concentration of substance differs on opposite sides of membrane, what occurs across the membrane?

Back 423

concentration gradient

Front 424

unless movement of molecules are restricted by the membrane, molecules will

Back 424

move across the membrane via diffusion

Front 425

what is determined by the magnitude of gradient, and continues until equilibrium occurs (energetically favourable)?

Back 425

Rate of diffusion

Front 426

the greater the concentration difference the more rapid the

Back 426

rate of diffusion

Front 427

the cell membrane restricts the movement of many molecules by diffusion, so the concentration of many substances is

Back 427

greater inside than outside the cell, which gives the concentration gradient

Front 428

what is the tendency for water to move from region of low solute concentration to region of high solute concentration?

Back 428

osmosis

Front 429

when cell is suspended in water, their is a net inflow of water due to

Back 429

osmosis, siunbce the cell membrnae is freely permeable to water

Front 430

during osmosis water is moving down concentration gradient by

Back 430

diffusion

Front 431

why does osmosis occur?

Back 431

to equalize the concentration of solutes and so water n either side of the membrane is favourable

Front 432

inflow of water swells cells and membrane expands to accommodate increase in water, water can keep entering until

Back 432

solute concentrations equalised on both sides of membrane or until pressure (turgor pressure) builds up in cell and prevents further flow of water

Front 433

what prevents osmotic pressure from stretching the membrane too far?

Back 433

cell wall

Front 434

the high concentration of dissolved solute inside the cell creates a pressure of about

Back 434

2 atmospheres (atm)

Front 435

when you treat with a lysosyme if intact cell still have some cell wall attached, this is called

Back 435

spheroplast

Front 436

an intact cell lacking a cell wall is called a

Back 436

protoplast

Front 437

if spheroplasts or potoplasts generated in an isotonic solution, they remain

Back 437

intact

Front 438

wht effect occurs when cells placed in solutions having high salt or sugar concentration (hypertonic solution)

Back 438

opposite effects occur

Front 439

Plasmolysis is where

Back 439

water flows out from bacteria by osmosis causing cell dehydration

Front 440

the effect on a cell when placed in a isotonic solution?

Back 440

normal cell

Front 441

what is the effect of a cell when placed in a hypertonic solution

Back 441

the cell is shrunken

Front 442

what is the effect on a cell when placed in a hypotonic solution?

Back 442

the cell bursts

Front 443

what is a rigid layer found in gram postive and gram negative but differs in thickness, it also helps maintain bacterial shape and integrity

Back 443

a peptidoglycan

Front 444

what is the importance of a peptidoglycan?

Back 444

it demonstrated by treating cells with lysozyme

Front 445

what do lysozymes specifically do?

Back 445

they digest peptidoglycan thus weakening the cell wall (osmotic lysis ensues if cell is in hypotonic environment)

Front 446

what is the main building material of the bacterial cell wall?

Back 446

a peptidoglycan

Front 447

what are polymers of sugar residues (glycans) cross linked by short stretches of amino acids (peptides)?

Back 447

peptidoglycans

Front 448

prokaryotes are

Back 448

bacteria

Front 449

what is the composition of petidoglycans?

Back 449

-two sugar derivatives: N-acetylglucosamine (G), and N-acetylmuramic acid (M) found in bacteria only and
Amino acids: L-alanine, D-alanine, D-glutamic acid, either L-Lysine or meso-diaminopimelic acid (DAP)

Front 450

D- amino acids are unusual (proteins L) peptidase

Back 450

resistant

Front 451

DAP diaminopimelic acid is found on all gram

Back 451

positive and some gram negative and never in eukaryotes

Front 452

in a peptidoglycan composition, components are connected to form

Back 452

repeating structure: glycan tetrapeptide (4 AAs).
X-linked to form a network around the cell

Front 453

in a peptidoglycan, peptide chains are bound to eachother by

Back 453

peptide x-links

Front 454

in a peptidoglycan, the greater the x-linking the greater the

Back 454

rigidity

Front 455

how do peptide cross links differ?

Back 455

-gram negative have direct interbridge and
gram positive have glycine interbridge

Front 456

gram positive have how many layers?

Back 456

up to 25 layers

Front 457

gram negative have how many sheets/layers?

Back 457

only 1 or 2 sheets

Front 458

the shape of a cell is determined by what two things?

Back 458

-its length of peptidoglycan chains and
-the manner and extent of cross linking

Front 459

when a cell grows, new cell wall material must be synthesised and added to pre-exsisting wall without causing

Back 459

autolysis

Front 460

peptidoglycan later must be loosesed to allow

Back 460

cell expansion,

loosening by autolysins (attack peptidoglycan components)

Front 461

what do glucosidases do?

Back 461

they attack sugar molecules

Front 462

what do endopeptidases do?

Back 462

they cut peptide bonds between amino acids

Front 463

in combindation what do autoolysisns, glycosidases and endopeptidases do?

Back 463

they create small openings in peptidoglycan layer, new wall amteriall added across openings

Front 464

what are the steps to add in new cell wall material?

Back 464

-following synthesis, glycan tetrapeptides transported to peptidoglycan lat

-bactoprenol transports glycan tetraptide across membrane to walls growing point

Front 465

what transports glycan tetrapeptide (pentapeptide) across the membrane to the cell walls growing point?

Back 465

a bactoprenol

Front 466

what is an isoprenoid alcahol that is recycled?

Back 466

bactoprenol

Front 467

what makes sugars sufficiently hydrophobic so that they can pass through the membrane?

Back 467

bactoprenol

Front 468

what blocks peptigoglycan synthesis by interfering with the supply of bactoprenol

Back 468

antibiotics such as vancomycin, ritocetin and bacitracin

Front 469

the final step in the manufacture of a new cell wall is the

Back 469

crosslinking of glycan tetrapeptides that occurs after they are exported across cell membrane

Front 470

crosslinking reaction termed transpeptidation is catalyzed by

Back 470

transpeptidases

Front 471

in gram negatives, transpeptidation involves

Back 471

one of the D-alanines in one glycan tetrapeptidr and DAP in another

Front 472

transpeptidases are inhibited by

Back 472

penicillins and cephalosporins

Front 473

antibiotics resemble a portion of glycan transpeptidase which results in

Back 473

a peptidoglyfcan without strength

Front 474

autolysis plus penicillin does what do peptidoglycan?

Back 474

severely weakens it

Front 475

autolysis and lysozyme disrupt glycosidic bonds between

Back 475

glycans

Front 476

penicillins and cephalosporins are effective only against

Back 476

growing bacteria

Front 477

what open up sites for insertion of new glycan tetrapeptides?

Back 477

autolysins

Front 478

once autolysins open sites for insertion of glycan tetrapeptides, the glycan tetrapeptides are added to the sites but penicillin prevents

Back 478

C-linking

the number of X-links in the cell wall decreases, wall strength diminishes, turgor pressure lyses cell

Front 479

the faster the organism multiplies, the faster the cell wall is

Back 479

replaced

Front 480

sensitivity of bacteria to penicillins and cephalosporins are dependent on what three things?

Back 480

1-amount of antibiotic able to reach growth site
2-affinity of transpeptidase for antibiotic
3-rate at which cells grow

Front 481

there is little pathogenic activity associated with the release of standard peptdoglycan subunits, however

Back 481

N-acetylmuramic acid is acetylated (COCH3) in some species

Front 482

when destroyed by defensive cells (phagocytes), peptidoglycan fragments are

Back 482

released into the body

Front 483

peptidoglycan fragments can induce

Back 483

fever and infection- associated arthritis, also Bordetella pertussis peptide fragments destroy ciliated epithelia of the respiratory tract

Front 484

what constitutes the outer membrane of Gram negative bacteria?

Back 484

-a lipid bilayer with protein containing lipopolysaccharide (Lipid linked to polysaccharide) forming outer half of membrane

Front 485

the outer membrane of gram negative bacteria have permeability to

Back 485

small ions and small hydrophilic molecules

Front 486

gram negative bacterial outer membrane provides

Back 486

structures and receptors that affect adhesion to host cells, resistance to phagocytosis, and susceptibility to bacteriophage

very different to other membranes

Front 487

gram negative cell has how many layers in its membrane?

Back 487

two layers

Front 488

gram negative bacteria consist of what three main types of molecules?

Back 488

1: Lipopolysaccharide (LPS)
2: Protein
3: Phospholipid

Front 489

what are the three distinguishable regions of "LPS" the first molecule of gram negative bacteria?

Back 489

-Lipid portion is lipid A
-the core polysaccharide contains ketodeoxyoctonate, 7-carbon sugars (heptoses), glucose, galactose
-)-polysaccharide, have a variety of 6 carbon sugars and can vary in response to host defenses

Front 490

LPS (lipopolysaccharide) layer (in particular lipid A) is responsible for

Back 490

toxicity of many Gram negative bacteria (salmonella, E coli, shigella to animals)

Front 491

Lipid A is a

Back 491

endotoxin

Front 492

lipid A is a endotoxin that creates symptoms of infection, what are the symptoms

Back 492

fever, shock, internal bleeding released when the bug dies

Front 493

lipid A is an endotoxin responsible for

Back 493

gram negative sepsis (systemic disease)

Front 494

Septic shock has what symptoms?

Back 494

fever, vascular collapse, renal failure, death

our immune system reacts to the O-polysaccharide

Front 495

the second molecule/layer "Protein" of gram negative bacteria has LPS plus various proteins which forms

Back 495

the outer half of outer membrane

Front 496

Lipoprotein (Braun's) anchors the inner membrane to the

Back 496

PG layer

Front 497

what are 1nm thick channel through which small molecules cross the membrane (it has 3 identical subunits that make a tube)

Back 497

porin

Front 498

what makes the outer membrane more permeable to small molecules than the cytoplasmic membrane?

Back 498

porins

Front 499

what are the two different kinds of porins?

Back 499

-nonspecific porins
-specific porins

Front 500

which kind of porins allow passage of only one or several related types of bigger molecles. they have specific binding sites for one or more substances?

Back 500

specific porins

Front 501

whch kind of porin allow passage of any small molecule (water filled channel), 600-700 daltons?

Back 501

nonspecific porins

Front 502

the third layer/molecule of gram negative bacteria "Phospholipids" are present only in the

Back 502

inner half of the membrane, and are the same as those found in cytoplasmic membrane

Front 503

Teichoice acids are gram

Back 503

positive (+)

Front 504

gram positives do not have an

Back 504

outer membrane, they have several layers of peptidoglycan encasing the cell

Front 505

acidic polysaccharides are called

Back 505

techoic acids

Front 506

what do teichoic acids attach?

Back 506

they attach to the plasma membrane (lipoteichoic acids) or to NAM of wall

Front 507

techoic acids consist of

Back 507

phosphate sugar (glycerol or ribotol) attached to other sugars and alanine

Front 508

what are negatively charged, major cell wall antigens?

Back 508

teichoic acids (TAs)

Front 509

how do teichoic acids promote bacterial survival?

Back 509

by serving as adhesins

adherence important for bacterial living on mucosal surface

Front 510

non-adherent bacteria is easily eliminated by fluid flow,
Disease causing ability usually dependent on

Back 510

ability to adhere

Front 511

what promotes septic like syndrome (systemic disease when large numbers of bacteria or their products circulate in blood)

Back 511

TAs (Teichoic acids)

Front 512

Teichoic acids cause host cells to release substances that promote

Back 512

inflammation,
can lead to cardiac dysfunction and other severe problems

Front 513

what is the space between the cell wall and cell membrane? it is not empty and contains many proteins, gell like consistency?

Back 513

Periplasmic space

Front 514

what serves as area of considerable enzymatic activity?

Back 514

periplasmic space

Front 515

what is involved in chemotactic response, and located in the periplasmic space?

Back 515

chemoreceptors

Front 516

what combines reversible with substrate molecules, concentrates them for membrane carrier proteins (ATP/Antigen binding cassette)

Back 516

Binding proteins

Front 517

most bacteria use what to move them, some use slimes?

Back 517

flagella

Front 518

what is 10-20nm wide and up to 2um long?

Back 518

flagella

Front 519

flagella attaches to cell in what different ways?

Back 519

-polar
and peritrichous

Front 520

polar flagella attachment is where the

Back 520

flagella attaches at one or both ends of the cell, polar flagella attachement can be
-monotrichous
-amphitrichous
-lophotrichous

Front 521

monotrichous has

Back 521

one flagella at one end

Front 522

amphitrichous has

Back 522

one flagella at each end

Front 523

lophotrichous has a

Back 523

tuft of several flagella at one or both ends

Front 524

the type of flagellation is species

Back 524

specific, meaning there are specific types of flagella on specific species

Front 525

Axial filaments/fibrils are similar to flagella and are found in

Back 525

spirochaetes (such as trepnema pallidum (syphillus) and Borrelia sp (lime disease))

Front 526

describe the structure of a flagella filament

Back 526

it has a portion extending into the environment, it is a helical structure

Front 527

what is the flagella filament composed of

Back 527

it is composed of flagellin subunits, and has a hollow core,

it has a filament, a hook, a basal body and a fili protein

Front 528

E coli has what sort of flagella?

Back 528

monotrichous

Front 529

where the flafellum contacts the cell differs in strcuture from the rest of the

Back 529

flagellum

Front 530

the hook structure of the flagella is a

Back 530

thicker, curved region at the base just outside the cell wall, consists of distinct protein subunits

Front 531

the flagella's basal body is the

Back 531

motor portion, anchored in the cell wall and membranes, the basal body is made up of rings and rods

Front 532

gram negative bacteria has how many rings

Back 532

4 rings

-L (LPS) rings
-P ring
-S ring
-M ring

Front 533

where is the L (LPS) ?

Back 533

it is anchored in the outer membrane

Front 534

where is the P ring?

Back 534

in peptidoglycan layer

Front 535

where is the S and M ring?

Back 535

they are anchored in the cytoplasmic/plasma membrane

Front 536

gram positive bacteria lacks

Back 536

outer pair of rings (L, LPS righ)

Front 537

Fli protein are between which rings?

Back 537

between the S and M rings which form a C ring, and act as a motor switch (alter direction in response to signals)

Front 538

what forms a C ring and act as motor switch (alter direction in response to signals)?

Back 538

Fli proteins

they determine the way flagella motor will spin

Front 539

8 Mot complexes surround which rings?

Back 539

the S and M rings

Front 540

each Mot complex includes

Back 540

4 mot A and 2 mot B subunits

Front 541

motA subunits pass through the

Back 541

cytoplasmic membrane, and are part of the protein in cytoplasm

Front 542

motB subunits are linked to motA subunits and anchored to

Back 542

peptidoglycan layer (ppg)

Front 543

gram negative has how many rings?

Back 543

4 rings

Front 544

gram positive lacks

Back 544

outer pair of rings

Front 545

the flagellar motor rotates at more than how many revolutions per second

Back 545

100

Front 546

initially S and M rings are inserted in the plasma membrane, components then pass through the channel in the S and M rings in

Back 546

strict order

Front 547

self assemblyoccurs according to

Back 547

structural information contained within the protein subunits

Front 548

flagella subunits have what kind of structure and core?

Back 548

they have a helical structure and a hollow core

Front 549

when the cell divides, additional flagella must be made, the way in which these are made depends in part on the

Back 549

type of flagellum

Front 550

there are two types of flagellum, what are they?

Back 550

-polar flagellation and
-peritrichous flagellation

Front 551

when brand new flagella forms at the location where the cell division occurs, this is known as

Back 551

polar flagellation

Front 552

when pre-existing flagella is distributed evenly between daughter cells, this is known as

Back 552

peritrichous flagellation

Front 553

flagella cells already start growing even before they

Back 553

split into daughter cells

Front 554

flagella grow and the original total number is

Back 554

restored

Front 555

describe flagella movement

Back 555

flagella doesnt flex, but rotates like a propella

its rod rotates within the rings

Front 556

energy for flagella rotation comes from the

Back 556

proton motive force

Front 557

the pmf allows flagella to

Back 557

spin

Front 558

the pmf determines the amount of

Back 558

speed the flagella spins

Front 559

Protons are transported across the cytoplasmic membrane by

Back 559

Mot proteins (1200 protons/rev)

Front 560

the speed of rotation varies with pmf, the max speed is

Back 560

300 rps (18000 rpm)

Front 561

the pmf propels the cell at around

Back 561

200um per second (up to 200 cell lengths/sec)

Front 562

bacteria has which two types of flagellation

Back 562

polar and peritrichous

Front 563

which bacterial flagellation tend to move more rapidly, and change direction often?

Back 563

polar flagellation

Front 564

which bacterial flagellation tend to move more slowly and in straight line

Back 564

peritrichous flagellation

(key: longer word than polar, therefore slower)

Front 565

what are helical, and push if rotate in one direction, and pull if rotate in ther other, like a drill or corkscrew

Back 565

flagella

Front 566

flagella is right or left handed helix?

Back 566

left handedthe flagellum rotates counterclockwise (CCW) to push forward and
clockwise (CW) to pull backward

Front 567

how is the flagella left handed helical structure?what are the directed movements of a bacterium?

Back 567

taxes

Front 568

what is the movement of microorganism towards/away from a chemical?

Back 568

chemotaxis

Front 569

how does chemitoaxis work?

Back 569

it senses gradient of chemical concentration in environment and moves according

Front 570

chemiattractants and chemorepellents are

Back 570

signal molecules

Front 571

in positive bacterial chemotaxis bacteria swim

Back 571

outwards following the gradient they have made

Front 572

in negative bacterial chemotaxis, bacteria swim

Back 572

away from disk of repellent

Front 573

what kind of microscopes have showed the two types of bacterial movements in peritrichous cells?

Back 573

tracking microscopes

Front 574

what are the two types of bacterial movements in peritrichous cells?

Back 574

-run and
-tumble

Front 575

during which bacterial movement in peritrichous cells does movement occur steadily in slightly curved line, the flagella rotate CCW, several bundle together, rotate in unison and push cell for 1 second

Back 575

run

Front 576

during which bacterial movement in peritrichous cells does movement not occur, just vibrates in spot, turning to face different directions; the flagella rotate CW (all pulling independently) bundle comes apart for around 0.1 second

Back 576

tumble

Front 577

what percentage of the time do flagella run and tumble?

Back 577

during normal behaviour, alternate run and tumble: Run (90-95%) and
tumble (5-10%)

Front 578

the choice of direction for Run is

Back 578

random and goes nowhere

Front 579

polar flagella rotate CW and CCW for

Back 579

equal periods

Run when rotating CW or CCW, cell is pushed when rotating CCW, and pulled for CW

Front 580

some polar flagella (Rhodomonas) are unidirectional, randomisation of direction at change over due to

Back 580

Brownian motion

Front 581

when is flagella movement not random

Back 581

in a gradient (chemical, temperature)

Front 582

the behavior of flagella movement in a gradient of attractant, there fewer tumbles, longer runs as organism experiences higher concentration of attractant. what is the net result?

Back 582

the organism moves up gradient

Front 583

the behavior of flagella movement during gradient of repellent, there are fewer tumbles, longer runs as organism experiences lower conncentration of repellent and the net result is

Back 583

movement down the gradient

Front 584

bacterium responds to a

Back 584

temporal and not a spatial gradient

(they have bad memory and respond to chemicals)

Front 585

the direction of flagella rotation is controlled by a

Back 585

signal transduction pathway

Front 586

what is a mechanism for sensing external environment/signal and transmitting awareness of signal to the intracellular target?

Back 586

signal transduction pathway

Front 587

what are chemireceptors that bind attractants or repellents?

Back 587

MEthyl-accepting chemotaxis prots (MCPs)

Front 588

what do MCPs do?

Back 588

they allow the cell to sense whether, over time, attractants or repellent concentration changes (cell too tiny to use spatial cues)

Front 589

what are transducers, that receive chemical and initiate process of changing signal into flagellar rotation?

Back 589

(MCPs) Methyl-accepting chemotaxis Prots

Front 590

cells must ignore past stimulus responses so they can compare most recent attractant concentration with immediately previous one because

Back 590

they have short term memory

Front 591

Fimbriae (fimbria) is structurally similar to flagella but contain

Back 591

different proteins

Front 592

how are fimbriea different to flagella?

Back 592

they are shorter, thinner and not involved in motility, and more numerous

Front 593

what is the function of fimbriae?

Back 593

cell adhesion to inert surfaces or each other (assist infection)

Front 594

fimbriae are found mostly on

Back 594

gram negative becateria

Front 595

what is strucurally similar to fimbriae, longer , often larger and only one or few per cell?

Back 595

Pili (pilus)

Front 596

what is function of Pili (pilus)?

Back 596

they function in transfer of genetic material between cells, receptors for viruses, attachment to human tissues for some pathogenic bacteria (only on gram negative bacteria)

Front 597

Pili (pilus) have capsules and slime, which is a

Back 597

stickly or gummy layer (outside of cell wall), composed of polysaccharides, proteins, polyalcahols, or amino sugars

Front 598

the Pili (pilus) layer is thick/thin depending on

Back 598

composition

Front 599

if the pili lrigid layers are organised very close together, it is called a

Back 599

capsule

Front 600

what helps bacteria resist phagopcytosis by host cells?

Back 600

Pili (Pilus)

Front 601

some pili structures are so large that the bacterial colonly looks mucold or sticky hence why it is called a

Back 601

Mucoid

Front 602

capsule ans slime contain water and can protect against

Back 602

dessication

Front 603

capsules and slime aid in attachment to

Back 603

solid objects or tissue surfaces

Front 604

if it is more easily deformed, water and does not exclude particles, it is called a

Back 604

slime layer

Front 605

what is the collective term for capsules and slime layers?

Back 605

Glycocalyx

Front 606

what is a material within the cytoplasmic membrane?

Back 606

Cytoplasm

Front 607

what has granular appearance, and is rich in RNA and Ribosomes?

Back 607

Cytoplasmuic area/matrix of the cytoplasm

Front 608

what is the part of the cytoplasm that is smoother in appearance, and rich in DNA?

Back 608

the nuclear area

Front 609

what part of the cytoplasm is rich in dissolved nutrients?

Back 609

Fluid portion

Front 610

what can be thought of as internal containers (reserviours of energy or structural material) and may be bound by a Non-unit membrnae (unilayer)?

Back 610

Inclusion bodies

Front 611

often the compounds stored in inclusions have unusual staining properties: such as

Back 611

-inorganic phosphate stored as polyphosphate, has negative charge so can be stained by cationic dyes
-Metachromatic granules are granules that stain with dye chaining color

Front 612

what are granules that stain with dye changing color?

Back 612

Metachromatic granules

Front 613

inclusion bodies also store

Back 613

sulfur, glycogen, and poly hydroxyalkanoates that are C/energy storage compounds

Front 614

what are small granular particles in the cytoplasmuic area that function in protein synthesis?

Back 614

Ribosome

Front 615

what is the size and diameter and composition of a ribosome?

Back 615

size expressed in terms of mass (80S in Euks) rate given in Svedberg units
~20nm in diameter
-60% RNA
40% protein

Front 616

what is the region that contains bacterial DNA?

Back 616

the Nuclear area

Front 617

what is a double stranded molecule in which subunits called nucleotides pair with each other?

Back 617

DNA

Front 618

how is DNA compacted?

Back 618

by folding (supercoiling) into distinct structure called nucleoid

Front 619

how many supercoiled domains are in a nucleoid?

Back 619

greater than 50

Front 620

how can dna be seen?

Back 620

can be seen in the Light microscope with special staining techniques

Front 621

a high density of DNA in the nucleus excludes ribosomes giving a

Back 621

smooth appearance

Front 622

what is nucleoids of Bacillus stained with?

Back 622

HCl Giesma

Front 623

what is DNA labelled by

Back 623

immuni EM

Front 624

what are aggregates of small, hollow cylindrical structures (gas vesicles) that enables the cell to be bouyant?

Back 624

Gas Vacuole/Vesicles

Front 625

what has a 2nm thick protein wall surrounding a hollow space?

Back 625

a vesicle

Front 626

how many vesicles per cell?

Back 626

usually around 100s/cell

Front 627

the shape of a vesicle is species

Back 627

specific

Front 628

the gas vacuole wall consist of

Back 628

-97% GvpA and
-3% GvpC

Front 629

GcpA forms a

Back 629

shell in which GvpA molecules are positioned adjacent to each other like ribs

Front 630

GvpA is very

Back 630

hydrophobic (water tight)

Front 631

GvpC strengthens vacuole wall by

Back 631

crosslinking to GvpA

Front 632

the shape of the Gas Vacuole wall is maintained by

Back 632

the rigid protein framework (unlike a lipid membrane)

Front 633

Gas vacuoles freely diffuse through the membrane and does not

Back 633

atore gases

Front 634

by the vacuoles keeping water out, the vesicle provides

Back 634

buoyancly, that is it reduces the density oif the organisms

Front 635

what is the density of a gas vacuole?

Back 635

5-20% that of the cell proper

Front 636

because Gas Vacuoles are impermeable to water, the composition and pressure of the gas inside the vacuole itself is

Back 636

the same as that of the gas in which the cell us suspended

Front 637

if bacteria with gas vesicles are kept in an air tight jar then the jar struck with a hammer, the cells will all

Back 637

sink, because the pressure has collapsed the wall of the vesicles

Front 638

cell division involved

Back 638

binary fission (two, L-fissum, to cleave)

Front 639

during binary fission, to make another cell, the main reactions rae

Back 639

polymerization reactions

Front 640

polymerization involves

Back 640

monomers (single units) combined with polymers (macromolecules)

Front 641

there are three key events in cell division, that are

Back 641

-DNA replication
-DNA segregation (partitioning)
-Cross wall (septum) formation

Front 642

binary fission (prokaryote) produces how many cells after division?

Back 642

two

Front 643

what is the flow of genetic information?

Back 643

DNA -> RNA -> protein (DRP)

Replication --> Transcription --> Translation (RTT)

Front 644

what is two complementary polynucleotide chains twisted to form a double helix?

Back 644

DNA

Front 645

DNA contain how many nucleotides?

Back 645

four

Front 646

what are the four nucleotides made up of in DNA?

Back 646

-each nucleotide is amde up of a sugar base (A, G, T, C) and a phosphate group

Front 647

in complementarty, what kind of bonds are between nucleotide bases?

Back 647

H bonds

Front 648

Nucleotides are held in a chain by

Back 648

phosphodiester linkages between adjacent nucleotide sugars

Front 649

in DNa bases pair across chains such that strand oriented in opposite direction, called

Back 649

antiparallel configuration

Front 650

which way does the DNA strand move?

Back 650

5 to 3 direction

Front 651

enzymes that make DNa are called

Back 651

DNA polymerases

Front 652

all DNA polymerases synthesis in the

Back 652

5 to 3 direction

Front 653

DNA chains are antiparallel, over chain growth is in the 5 to 3 direction on one strand and

Back 653

3 to 5 on the other (laggin strand)

Front 654

in bacteria (prokaryotes), replication is

Back 654

Bidirectional in the circular bacteria genome

Front 655

in bacteria, there are two replication forks on the circular DNA that have started at

Back 655

ori (origin)

Front 656

DNA polymerases add dNTPs only onto

Back 656

preexsisting polynucleotide chain

Front 657

DNA polymerases are initiated by relatively short

Back 657

RNA primers usually made by primases

Front 658

in DNA polymerases, Primers are later removed and replaced with

Back 658

DNA

Front 659

Okozaki fragments are found on the

Back 659

lagging strand

Front 660

the laggin strand has what sort of replication

Back 660

discontinuous replication

Front 661

the leading strand is synthesised

Back 661

continuously

Front 662

in DNA segregation, each new DNA molecule attaches to the

Back 662

cell membrane

Front 663

after replication each new DNA that attaches to cell membrane, have points of attachment that are pushed away from each other by

Back 663

insertion of new membrane between the 'points of attachment'

Front 664

during septum formation, growing rod shaped cells elongate to

Back 664

2x cell length

Front 665

the septum forms and seperates the cell into

Back 665

two daughter cells

Front 666

the septum is formed by an

Back 666

inward growth of cell membrane and wall

Front 667

FtsZ forms a

Back 667

ring in dividing bacteria

Front 668

FtsZ forms a ring at what location

Back 668

at the Isthmus of dividing bacteria

Front 669

a 'divisome' controls

Back 669

synthesis of new membrane and cell wall material in both directions

Front 670

FtsZ ring depolymerises and triggers an

Back 670

inward growth of wall material (thus creating the division of the bacterial cell into two daughter cells)

Front 671

FszA is targeted to the

Back 671

mitochondria of Dictyostelium

Front 672

what are specialised structure formed within a cell to ensure survival under harsh environmentsal conditions such as heat, radiation , acids, etc?

Back 672

Endospores

Front 673

Endospores are membrers of the genera

Back 673

Bacillus, Clostridium

Front 674

what is bacillus clostridium?

Back 674

a sport forming bacteria that cause anthrax, botulism, tetanus, gas, gangrene, colitis

Front 675

in order to kill an endospore you need to

Back 675

put under 121 degrees Celsius for 20 minutes

Front 676

endospores are usually imbermeable to stains, but are easily visible as unstauined region in stained cell because they are highly

Back 676

refractile (from the word refract light)
(they change direction of the light passing through them)

Front 677

a spore is formed from a

Back 677

vegetative cell

Front 678

endospore stains have been developed through

Back 678

malachite green

Front 679

the three types of intracellular spore locations are

Back 679

-terminal
-sub-terminal
-central

Front 680

in a spore structure the Exosporium is a

Back 680

thin delicate covering (often present)

Front 681

in the spore structure, its spore coats are

Back 681

several layers of greater than 25 spore specific proteins (impermeable and lysozyme resistant)

Front 682

in a spore strucutre, its cortex is

Back 682

layers of loosely cross linked peptidoglycan

Front 683

the core or spore protoplast of a spore is

Back 683

similar to a cell, bounded by a cell wall (core wall) and a cytoplasm membrane

Front 684

the spore moves from 75 to 15% water, the reason why spores are so

Back 684

resistant to degredation

Front 685

the core/protoplast contains

Back 685

cytoplasm with ribosomes, nucleoid, no mRNA and few tRNAs, and a few enzymes

Front 686

in the endospore core, amino acids are stored as

Back 686

small acid soluble proteins

Front 687

why are spores so resistant?

Back 687

-core contians dipicolinic acid complexes with calcium (10%)

Front 688

what does dipicolini acid do

Back 688

it brings calcium into contact with peptidoglycan

Front 689

what does the calcium X-link to

Back 689

to peptodoglycan

causes contraction and expulsion of water

(causing the 75 to 15% decrease in water in core)

this contributes to heat and chemical resistance, inactivates enzymes in the core

Front 690

the pH of the endospore core is about

Back 690

1 unit lower than normal

Front 691

the core also contains small acid soluble proteins that bind tightly to

Back 691

DNA
and protect it from damage by UV, dessication, dry heat

Front 692

in the spore core, DNA is locked into a

Back 692

stable, relatively dessicated, crystalline state

Front 693

Small acid soluble proteins also function as

Back 693

carbon and energy source for outgrowth of new cells from spore

Front 694

there are how many distinct steps in spore formation?

Back 694

seven

Front 695

spore formation (sporulation) does not occur when cells are

Back 695

actively growing

Front 696

sporulation is triggered by

Back 696

cessation of growth at high density due to nutrient depletion(an example is Bacillus that starts sporulating if C and N are limited)

Front 697

what are the seven stages to spore formation?

Back 697

1-nutrient run low
2-2 copies of DNA formed
3-engulfment
4- exosprium forms cortex oprecursos
5-calcium incorporated
6-final corgtical latyer formed
-7- cell breaks, spore realeases

Front 698

describe the first step of sporulation in detail

Back 698

(key: sun)

nutrients run low, DNA density increases, membrane beings invaginating, 1 copy of DNA migrates to spore region

Front 699

describe the second step of sporulation in detail

Back 699

the membrane completes invagination process, the spore septum forms, and 2 copies of DNA are separated'

(key: shoe)

Front 700

describe the third step of sporulation in detail

Back 700

the spore septum surrounds one of the two nuclear regions = engulfement

forms iunnner and outer spore membranes

(key: tree)

forms forespore, a process which is not reversible once this stage is reached, the cell is commited

a cell that contains forespore is called sporangium

Front 701

after the 3rd stage of spore formation (sporulation) there is no

Back 701

turning back and the cell is commited to forming the endospore

Front 702

describe the fourth step of sporulation in detail

Back 702

the exosporium forms a cortex precursor (primordial cortex) forms between the membrane layers

(key: door)

Front 703

describe the fifth step of sporulation in detail

Back 703

calcium is incorporated into spore, complexes with DPA

SASPs (small acid soluble proteins) is produced, and the spore coat layers are formed

(key: hive)

Front 704

describe the sixth step of sporulation in detail

Back 704

the final cortical layer is formed, heat and chemical resistance develops at this stage
(key: stix)

Front 705

describe the seventh step of sporulation in detail

Back 705

(key: heaven)

the cell breaks down, the spore is realeased

Front 706

what is an example of a dorment spore?

Back 706

anthrax

Front 707

spore germination happens when things are good again (after a dorment spore outbreak) and involves what three steps?

Back 707

1: activation
2: germination
3: outgrowth

(key: ago)

Front 708

describe the first step of spore germination

Back 708

activation: cessation of dormany , induced by heating

Front 709

describe the second step of spore germination

Back 709

germination: activated spores germinate in presence of specific nutrients

activates protease that releases and activates cortex specific lytic enzyme

-Lytic enzyme degrades cortex allowing inflow of water and nutrients, becomes less retractile and can now be easily stained

Front 710

describe the third step of spore germination

Back 710

Outgrowth: the cell hydrates and visible swells

RNA, Protein, and DNA synthesis starts

the spore coat breaks due to swelling, the cell emerges and starts to grow

Front 711

what is a nucleotide that is the primary form in which chemical energy is conserved and utilized in cells

Back 711

ATP

Front 712

what is an enzyme containing an active site for binding substrate and an allosteric site for binding an effector molecule such as the end product of a biochemical pathway?"

Back 712

allosteric enzyme

Front 713

what is the sum total of all biosynthetic reactions in the cellwhat is a form of respiration in which oxygen is absent and alternative electron acceptros are reduuced?

Back 713

anabolic reactions (anabolism)anaerobioc respiration

Front 714

what are manipulations to prevent contamination of sterile objects of microbial cultures during handling

Back 714

aseptic technique

Front 715

what is a multiprotein enzyme complex embedded in the cytoplasmic membrane that catalyses the synthesis of ATP coupled to dissipation of the proton motive formce

Back 715

ATPase (ATP synthase)

Front 716

what is an organism capable of biosynthesizing all cell amterial from carbon dioxide as the sole carbon source?

Back 716

autotroph

Front 717

what is a biochemical reaction leading to energy conservation (usually ATP) by the cell

Back 717

catabolic reactions (cataboism)

Front 718

what is an organism that can grow with inorganic compounds as electron donors in energy metabolism?

Back 718

chemolithotroph

Front 719

what is a small and loosely bound non-protein molecule that participates in a reaction as part of an enzyme?

Back 719

coenzyme

Front 720

what is a culture medium composed of chemically undefined substances such as yeast and meat extracts

Back 720

complex medium

Front 721

what is an aqueous solution of various nutrients suitable for the growth of microorganisms?

Back 721

culture medium

Front 722

what is a cuklture medium whos precise chemical composition is known

Back 722

defined medium

Front 723

what is a substance that can accpet electrons from an electron donor, becoming reduced in the process?

Back 723

electron accpetor

Front 724

what is a substance that can donate electrons to an electron acceptro, becoming oxidized in the process?

Back 724

electron donor

Front 725

endergonic reactions

Back 725

require energy

Front 726

exergonic reactions

Back 726

release energy

Front 727

what is feedback inhibition?

Back 727

a process in which an excess of the end product of a multistep pathway inhibits activity of the first enzyme in the pathway

Front 728

what is fermentation

Back 728

an anaerobic catabolism in which an oprganic compound is both an electron donor and an electron acceptor and ATOP is produced by substrate level phosphorylation

Front 729

what is energy available to do work (delta zero) is free enrgy under standard conditions

Back 729

free energy (delta G)

Front 730

what is a biochemical pathway in which glucose is fermented, yielding ATP and various fermentation products, also called the Embden Meyerhof Parnas pathway?

Back 730

Glycolysis

Front 731

what is the sum total of all the chemical reactions in a cell

Back 731

metabolism

Front 732

what is the production of ATP from a proton motive force formed by electron transport of electrons from organic or inorganiuc electron donors?

Back 732

oxidative phosphorylation

Front 733

what is an organism that use lifht as their source of energy

Back 733

phototrophs

Front 734

what is a source of energy resulting from the separation of protons from hydroxyl ions across the cytoplasmic membrane, generating a membrane potential

Back 734

proton motive force

Front 735

what is acultire that contains a single ckind of microorganism?

Back 735

pure culture

Front 736

he essential element needed by a cell for synthesis of nucleic acids and phospholipids is:

Back 736

phosphorus.

Front 737

what is considered a nutrient needed by certain fastidious microorganisms for growth?

Back 737

Vitamins

Front 738

The small nonprotein molecules that are not substrates, are required for catalysis, and are only loosely bound to enzymes are known as:

Back 738

coenzymes.

Front 739

Growth of microorganisms on a solid medium can be seen by the formation of:

Back 739

colonies.

Front 740

The pH gradient and electrochemical potential that form during electron transport processes in aerobic respiration are collectively called the:

Back 740

proton motive force.

Front 741

Electron transport and the proton motive force are common in many types of catabolism. What is the form of catabolism in which these do NOT occur?

Back 741

Fermentation

Front 742

The ability of a substance to become oxidized or reduced is known as its

Back 742

reduction potential

Front 743

A _________ medium contains compounds that selectively inhibit the growth of some microorganisms, but not others.

Back 743

selective

Front 744

A _________ medium is one in which an indicator is added to allow for the differentiation of particular chemical reactions that have occurred during growth.

Back 744

differential

Front 745

The amino group of amino acids is typically derived from what source in the environment?

Back 745

An inorganic nitrogen source

Front 746

In addition to completing the oxidation of glucose during respiration, the citric acid cycle is important for which processes?

Back 746

The synthesis of amino acids using α-ketoglutarate and succinate as precursors

Front 747

The synthesis of amino acids using α-ketoglutarate and succinate as precursors

Back 747

membranes.

Front 748

Autotrophic microorganisms get their nutrition by:

Back 748

using CO2 and light energy to synthesize carbohydrates.

Front 749

Most bacteria require vitamins for their growth. In the cell, vitamins function as:

Back 749

co-enzymes.

Front 750

Defined culture media are made by

Back 750

adding precise amounts of purified organic and inorganic chemicals to distilled water.

Front 751

Feedback inhibition is a strategy for:

Back 751

shutting off the enzymes of a pathway when there is excess product.

Front 752

Microorganisms that are fastidious, i.e., difficult to grow,:

Back 752

can be grown with the addition of nutrients such as serum to a complex medium.

Front 753

Escherichia coli can be grown on a simple defined medium, but Leuconostoc mesenteroides does not grow on this medium. This is because:

Back 753

Leuconostoc mesenteroides requires several nutrients for growth that E. coli does not.

Front 754

Using a sterile inoculating loop to transfer liquid culture from one tube to another is an example of:

Back 754

aseptic technique.

Front 755

For most compounds the free energy Gf0 is negative. This means that:

Back 755

the compound can form spontaneously from its elements

Front 756

Enzymes are cellular catalysts. This is because:

Back 756

they lower the activation energy of a reaction, thereby increasing its rate.

Front 757

Redox reactions in microbial cells require small molecules to serve as electron carriers. An example of an electron carrier is:

Back 757

NAD+.

Front 758

ATP is an important compound in all living cells. This is because:

Back 758

it is an energy-rich compound, that can be broken down to liberate energy for cellular functions.

Front 759

What are the products of glycolysis?

Back 759

ATP and fermentation products

Front 760

The proton motive force is generated by the movement of electrons across a membrane, so that the two sides of the membrane differ in both charge and pH. This proton motive force is essential for what?

Back 760

Synthesis of ATP

Front 761

gram positive cocci is morphologically consistant with

Back 761

staphylococci species

Front 762

gram positive cocci in chains is suggestive of

Back 762

streptococcus

Front 763

in a peptidoglycan, what holds the peptides (amino acids) together?

Back 763

a pentaglycine interbridge holds the peptide (amino acid) chain that holds N acetylmuramic acid and N acetylglucosamine to form a complete peptidoglycan

Front 764

are the interbridges the same in gram positive and gram negative bacteria?

Back 764

no

Front 765

in gram negative bacteria such as E.coli, what peptides are bonded onto the peptide interbridge?

Back 765

D-Ala and DAP, which is a direct interbridge

Front 766

in gram positive bacteria such as S.aureus, what kind of peptides are bonded to the interbridge in a peptidoglycan?

Back 766

a glycine interbridge is found, where the two peptides D-Ala and L-Lys forms the interbridge between the amino acids (peptides)

Front 767

in gram negative or positive does transpeptidation involve one of the D-Ala (D-alanines) in one glycan tetrapeptide and DAP in another, resulting in a D-Ala on one tetrapep being lost?

Back 767

in gram negative bacteria this occurs

Front 768

Transpeptidases are inhibited by

Back 768

penicillins and cephalosporins

Front 769

eukaryotic cells include which 5 variations?

Back 769

1: Fungi
2: plants
3: algae
4: protozoa (protists)
4: animals

(Key:FPAPA)

Front 770

in euks DNA and RNA synthesis occurs in the

Back 770

nucleus

Front 771

in euks, protein synthesis occurs in the

Back 771

cytoplasm

Front 772

euks have other functions localized to other membrane structures called

Back 772

organelles

Front 773

there is no intermediate cell type between prokaryotes and eukaryotes however which one has characteristics similar to eukaryotes?

Back 773

archaea

Front 774

which three have a universal ancestor?

Back 774

domain bacteria, domain archaea and domain eukarya

Front 775

the cellular tree of life is lalrgely one of

Back 775

m,icrobes, even the eukaryotes

Front 776

different algae have different mitochondria and have come from different backgrounds, therefore they are

Back 776

phylogenetically diverse

Front 777

in the bacterial tree of life, the root for the eukaryote tree is between

Back 777

apisthakonts and excavates

Front 778

the shapes of euk cells are distinctive in comparison the the genetically simpler shapes of

Back 778

proks

Front 779

the different kinds of eukaryotes are based on

Back 779

wall type, if present

Front 780

a cell wall is the material

Back 780

outside the plasma membrane

Front 781

a cell wall is present in

Back 781

algae, fungi and plant cells

Front 782

a cell wall is absent from

Back 782

animal cells and most protozoa

Front 783

a cell wall is visible with a

Back 783

light microscope

Front 784

some excavates are thought to be

Back 784

ancient

Front 785

some cells were thought to have no mitochondria like______ however it is now known they once had mitochondria

Back 785

giardia lamlia

Front 786

giardia lamlia are mostly

Back 786

parasitic and have no wall

Front 787

euglenoids (discicristates ) are mostly ___________________ and closely related to ________________

Back 787

photosynthetic (no cell wall),
trypanosomes

Front 788

Euglenoids have what kind of cell wall?

Back 788

pellicle type

Front 789

a trypanosome (kinetoplastid) has a very unusual

Back 789

mitochondria

Front 790

what causes african sleeping sickness and leishmaniasis?

Back 790

Trypanosomes

Front 791

what spreads trypanosomes?

Back 791

the Tsetse fly

Front 792

what is a rigid layer below the plasma membrnae, proteinaceous strips shaped by MTss, and the strips move against one another?

Back 792

Euglenoid pellicle

Front 793

what also have a pellicle that gives shape to small unicellular phytoplankton and have different variations of pigment depending on each phytoplankton?

Back 793

Cryptophytes

Front 794

what have no cell wall and extened pseudopods to get around (actin based motility)?

Back 794

Amoebae

Front 795

pseudopods dont have a cell wall,they have

Back 795

filtering phagocytic vacuoles (moving arms) that looks like octopus shape and they are constantly moving

Front 796

amoeba undergo

Back 796

dictyostelium (meiosis) and slime molds

Front 797

a slime mold produces

Back 797

fruiting bodies (haploid) and different structures they can maintain

Front 798

after dictyostelium and meosis is complete the next stage is

Back 798

binary fission

Front 799

what cell contains many parasites and dinoflagellate 'algae'?

Back 799

the Alveolata (a Plasmodium)

Front 800

does the alveolata (plasmodium) contain a cell wall?

Back 800

no

Front 801

plasmodium

Back 801

dinoflagellates (alveolata) are

Front 802

what is the causative agent of malaria?

Back 802

plasmodium falciparum

Front 803

paramecium fall under which category

Back 803

plasmodium

Front 804

dinoflagellates (alveolatra) are

Back 804

phytoplankton that can sometimes bloom to plague proportions and kill fish and produce toxins dangerous to humans

Front 805

what makes up the cell wall of Dinoflagellates (Alveolata)?

Back 805

Algal (cellulosic) plates

Front 806

algal (cellulosic) cell walls are made up of

Back 806

cellulose, with a polymer of up to 8000 glucose units, that are 4um in width

Front 807

cellulose molecules intertwined to form___________________ and_____________ overlap to form wall structure

Back 807

microfibrils 30-50nm diameter and the microfibrils overlap to form the wall structure

Front 808

the strength of the cellulosic wall increases by the amount of

Back 808

polymers of mannose and xylose (sugars)

Front 809

some algae have walls of scales made from

Back 809

silica or calcium carbonate (gives its shape)

Front 810

diatoms cell walls have

Back 810

silica and frustules, and chlorophylls a & c

the sylica helps maintain the location of water born cells

Front 811

what have one long hairy flagellum, and a shorter smooth flagellum?

Back 811

Heterokonts (stramenopiles)

Front 812

why cant silica be seen clearly via electron microscope?

Back 812

silica are electron dense

Front 813

haptophytes are mostly

Back 813

oceanic phytoplankton

Front 814

hapotophytes are big primary producers of

Back 814

carbon (>10% earths Petrollium)

Front 815

hapotophytes are covred in

Back 815

scales which may be calcified

Front 816

name two haptophytes

Back 816

-pleurochrysis carterae and
-the coccolithophorid (gephyrocapsa oceanica)

Front 817

haptophyte scales are

Back 817

individuel wall elements (shields or spines)

Front 818

the scales of haptophytes are made of

Back 818

sugars

Front 819

the scales of hatophytes are assembled in the

Back 819

golgi apparatus before deposition on to the cell surface

Front 820

haptonema inserts between

Back 820

flagella and Bbs

Front 821

Haptonema's flagellum has appeendage, coiled and extending 50 um) that is

Back 821

unique to the group

Front 822

pleurochrysis carerae (haptophyte alga, or coccolithphid), calcium carbonate rims around polysacchardies, scales (coccoliths) are made in the _______ and transported to the cell surface in_________

Back 822

made in the Golgi and transported to the cell surface in vesicles

Front 823

polysaccharides are polymerized in a______________________pattern to make scales (CaCO3) ppts around rim in TGN for scale to be a coccolinth)

Back 823

Species-Specific

Front 824

which species of cell wall have some made of callulose, but most made of glucan (amorphic polymer of glucose) plus Chitin?

Back 824

Fungal cell wall

Front 825

what increases rigidity of fungal cell wall and is a polymer of N-acetylglucosamine

Back 825

Chitin

Front 826

what is the difference between fungal and normal bacterial cell wall?

Back 826

the fungal cell walls have oligosacharides on the top of their membrane instead of polysaccharides

Front 827

Opsthokonts in the genera tree include

Back 827

animals and fuingi

Front 828

what are Protozoan shells

Back 828

they are a poorly understood chemical structure,

Front 829

what are Protozoan shells constructed by?

Back 829

a protein-polysaccharide matrix called pseudochitin, cellulose, silica, calcium carbonate

Front 830

what are two species that have protozoan shells?

Back 830

Nodosira (amebioprotist) and
Dicttyocha

Front 831

Nodosira is a

Back 831

foraminiferan (amebioprotist)

Front 832

Dicttyocha is a

Back 832

silicoflagellate

Front 833

the Sarcodine (Arcella) has what kind of cell wall

Back 833

a Test wall of chitin like material

Front 834

eukaryotes have _________ which are a form of a lipid

Back 834

sterols

Front 835

sterols make a membrane more

Back 835

rigid, less leaky

Front 836

eukaryotes are bigger than ___________ because there may be a bigger stress on the ____________ membrane

Back 836

euks are bigger than proks, because bigger stress on euk membrane

Front 837

__________antibiotics (nystatin, candicidin) react with sterols and destaboolose the membrane

Back 837

polyene antibiotics

Front 838

the cytoplasmic matrix is featureless, and contains a homogenous substance, it is made of ________ water with two different forms of water

Back 838

70-85% water

Front 839

what are the two different forms of water in the cytoplasm?

Back 839

-Bulk water
-free water

the water that is bound to the surfaces of macromolecules is osmotically incative

Front 840

the protein content of the cytoplasmic matric is so high that it may be

Back 840

semi crystalline

Front 841

the cytoskeleton contains what three subunits?

Back 841

-Microfilaments
-Microtubules
-Intermediate filaments

Front 842

what is 25 nm diam cylinder composed of two different tubulin subunits (alpha, beta) arranged helically and involved in three things:
1: Maintaining cell shape and
2: cell movement and
3: intracellular transport

Back 842

Microtubules

Front 843

what is 8-10 nm and made if Keratin arranged in fibrous subunits?

Back 843

Intermediate filaments

Front 844

what is 4-7nm diam protein filaments scattered within the cytoskeleton matrix, or in ordered networks or arrays of actin?

Back 844

Microfilaments

Front 845

microtubules can be viewed via what microscopy?

Back 845

confocal microscopy

Front 846

microtubules are famous for their role in

Back 846

mitosis

Front 847

the cytoskeleton allows for _________________ and __________________

Back 847

cellular movement and organelle translocation

Front 848

the membranes of some organelles are _____________, other membranes __________ ______of membrane via budding and fusion of__________

Back 848

the membrane of some organelles are continuous (nuclear membrane and endoplasmic reticulum), other membranes exchange sacs of membrane via budding and fusion of vesicles

Front 849

organelles of the endomembrane system include what 5 organelles?

Back 849

1: Nuclear membrane
2: Endoplasmic reticulum
3: Golgi apparatus
4: Lysosomes
5: Vacuoles

(Key: NEGLV: in the endomembrane system (ES) nearly everyone gets lovely valentines)

Front 850

the endoplasmic reticulum (ER) has a membranous labytinth which accounts for ________% of the total membrane?

Back 850

>50%

Front 851

in the ER there is a netweok of membranous tubules and sacs called

Back 851

cisternae

Front 852

the cisternae seperates the

Back 852

internal cisternal space from the cytosol

Front 853

in the ER the cisternae increases the __________

Back 853

surface area

Front 854

in the ER the cisternae also connects the

Back 854

cell surface to the internal structures

Front 855

there is two kinds of ER, which are

Back 855

Smooth and rough

Front 856

which type of ER functions in lipid synthesis, carbohydrate metabolism, detoxification of drugs and poisons?

Back 856

the smooth ER

Front 857

which type of ER is studded with ribosomes, and is a site of protein synthesis?

Back 857

Rough ER

Front 858

there are proteins used elsewhere and are transported in vesicles that were budded off from part of the ET and they are called

Back 858

Transitional ER

Front 859

what exsist free in the cytoplasm or bound to the ER?

Back 859

ribosomes

Front 860

what proteins are produced/made on free ribosomes?

Back 860

Cytoplasmic proteins

Front 861

what kind or proteins are produced/made on the ER bound ribosomes?

Back 861

Membrane proteins and SEcreted proteins

Front 862

cells with high rates of protein synthesis have many

Back 862

ribosomes

Front 863

some newly produced/synthesised proteins possess a

Back 863

signal sequence

Front 864

the signal sequence on newly made proteins targets them to the

Back 864

ER

Front 865

membrane proteins (made by bound ribosomes) possess what kind of sequences and what do they do?

Back 865

transmembrane sequences and insert into the membrane of the ER

Front 866

once targeted and inserted into the ER, the proteins are

Back 866

folded and glycosylated

Front 867

what organelle consist of a stack of flattened membranous cisternae?

Back 867

Golgi apparatus

Front 868

what functions does that Golgi have?

Back 868

it functions in manufacturing, warehousing, sorting and shipping

(Key: MWSS: The Golgi must wear silly socks)

Front 869

The Golgi apparatus often modifies

Back 869

the sugars on proteins to be sercreted of transported to another compartment

Front 870

describe the polarity of cisternae

Back 870

cisternae at opposite ends of the stacks have different thickness and composition (thus polarity)

Front 871

in the Golgi, what is located near the ER and receives transport vesicles?

Back 871

the Cis face

(Key: Golgi's sis is near the ER and receives budded transport vesicles)

Front 872

in the Golgi, what part buds off vesicles containing material for travel to the other sites?

Back 872

Trans-face

Front 873

in the Golgi, material may be modified as it passes from

Back 873

the Cis to the trans faces

Front 874

different cisternae contain diffeernt teams of

Back 874

enzymes

Front 875

in the Golgi, before products are dispatched from the trans face they are

Back 875

moleculary tagged for different destinations

Front 876

what are membrane enclosed sacs within a cell and are larger than vesicles?

Back 876

Vacuoles

Front 877

what kind of vacuoles are a protozoa that ingest food particeles via phagocytosis?

Back 877

food vacuoles

Front 878

how does a food vacuole phagocytose?

Back 878

particles become surrounded by it membrane, and then the vacuole fuses with the lysosome

Front 879

what kind of vesicles import small volumes of surrounding liquid (and membrane)?

Back 879

Pinocytotic vesicles

Front 880

what are the two types of Endocytosis?

Back 880

Phagocytosis and Pinocytosis

Front 881

what kind of vacuole is found in freshwater protists?

Back 881

Contractile vacuoles

Front 882

how do contractile vacuoles enlarge?

Back 882

by taking up water and waste materials

Front 883

how do contractile vacuoles expels contents?

Back 883

through there membrane to the cell exterior

Front 884

what is a single membrane enclosed gas of hydrolytic enzymes (hydrolases) that digest macromolecules (polysaccharides, fats, proteins, NAs)?

Back 884

Lysosomes

Front 885

what conditions do lysosomes work best under?

Back 885

slightly acidic conditions (pH 3.5-5.0)

Front 886

lysosomal membrane imports what to keep pH low?

Back 886

Hydrogen ions

Front 887

an enzyme release from a single lysosome into the cell is not serious since

Back 887

cytosolic pH is ~7

Front 888

lysosomes are formed by

Back 888

budding from tras gacec of the Golgi

Front 889

lysosomal enzymes and membrane are made by the_____ and transferred to the _____

Back 889

RER and transferred to the Golgi for packaging and processing

Front 890

what precents self desruction of the lysosomes

Back 890

3D conformation of inner surface of lysosomal membrane and enzymes themselves

Front 891

lysosomes function in both

Back 891

Phagocytosis and Autophagy

Front 892

Phagocytic and Autophagic vesicles are collectively called

Back 892

endosomes

Front 893

lysosomes function in

Back 893

endosomes

Front 894

1ry (primary) lysosomes fuse with phagocytic/autophagic vacuoles to make

Back 894

2ry (secondary) lysosomes

Front 895

what breaks down the ingested material after the phagocytic/autophagic vacuoles fuse lysosomes and, organic monomers returned to cytosol?

Back 895

enzymes

This is how human liver cells recycle half their macromolcules

Front 896

a residual body is a

Back 896

lysosome with lots of indigestible material

Front 897

the Complex of ER, Golgi, lysosomes, phagocytic and autophagic vacuoles operates as a coordinated whole to import and export material is known as

Back 897

membrane flow

Front 898

ER makes secretory proteins and membrane that contributes these to the

Back 898

Golgi

Front 899

the membrane flow all starts in the _____ and there is a flow from the _____ to other parts of the cells

Back 899

ER, ER

Front 900

The Golgi forms both

Back 900

1: secretory vesicles and
2: lysosomes

Front 901

the traffic of membrane movement between the Golgi and plasma membrane is

Back 901

two way traffic

Front 902

in membrane flow, empty vesicles are

Back 902

recycled and returned to the golgi or Plasma membrane

Front 903

microbodies are a specialised

Back 903

metabolic compartment bounded b a single membrane

Front 904

peroxisomes contain what enzyme?

Back 904

catalase enzyme which converts H2O2 to water

Front 905

peroxisomes grow by

Back 905

incorporating lipids and proteins from the cytoplasm, increasing in number by splitting in two when reach they reach a certain size (not made by endomembrane system)

Front 906

mitochondria (single: mitochondrion) have the main function of

Back 906

ATP generation by electron transport and oxidative phosphorylation

Front 907

mitochondrions are around _____um in diameter and _____um long

Back 907

0.3-1 um diameter and
5-10um long

Front 908

the mitochondria have an envelops of two membranes, each a

Back 908

phospholipid bilater

Front 909

mitochondria lack ______in their lipid bilayers

Back 909

sterols

because they are bacterial (prokaryotic) derived

Front 910

the intermembrane space and mitochondrial matrix have three things:

Back 910

outer membrane,
inner membrane
matrix

Front 911

the outer membrane has

Back 911

smooth protein channels (porins) that allow a passage for molecules of up to 10000 Daltons

Front 912

the inner membrane has

Back 912

many infoldings (cristae), proteins regulate the passage of metabolites into and out of the matrix

Front 913

the Matric is

Back 913

a gel like consistency, with large amounts of protein including some enzymes for respiration (TCA cycle)

Front 914

the Krebs Cycle (TCA cycle ) is present in

Back 914

mitochondrial matrix

Front 915

mitochondria contain what kind of

Back 915

mDNA (mitochondrial DNA)

Front 916

mitochondria contain how many ribosomes

Back 916

70S

Front 917

in the mitochondria most proteins are encoded in the

Back 917

nucleus and imported

Front 918

imported proteins have a leader or adress label that is

Back 918

clipped off, on entry into the organelle

Front 919

imported proteins move around in the cell change shape and

Back 919

divide into two

Front 920

what contains chlorophyll and enzymes that function in photosynthetic food production?

Back 920

chloroplasts

Front 921

plaint cells contain ___________ instead of __________ in bacteria derived mitochondria

Back 921

chloroplasts, instead of mitochondria

Front 922

chloroplasts are most often ________shape and ______2-4um wide and ______um long

Back 922

oval,
2-4 um wide
5-10um long

Front 923

chloroplasts have an envelope of two membranes, a very permeable outer membrane and a less permeable inner membrane, that are seperated by a narrow

Back 923

intermembrane space

Front 924

in a chloroplasts, what holds the membranous system arranged in flattened sacs called thylakoids?

Back 924

interior of chloroplasts (Stroma)

Front 925

in some regions, thylakoids are stacked to form a structure called

Back 925

grana

Front 926

the hydrophobic part of the chloroplast associates with the

Back 926

thylakoid membrane

Front 927

do chloroplasts contain DNA and ribosomes?

Back 927

yes

Front 928

how do chloroplasts form?

Back 928

by the division of preexisting chloroplasts (binary fission-like bacteria)

Front 929

what are supporting facts/statements for the endosymbiotic theory of euk cell formation: where mitochondria and chloroplasts descended from proks and invaded euks

Back 929

-mitochondria and chloroplasts contain circular DNA
-DNA encodes some organelle components needed for protein synthesis and respiration
-mitochondria and chloroplasts contain 70S ribosomes
-Antibiotics that block the 70S ribosomes function, inhibit protein synthesis in mitochondria and chloroplasts
-DNA encoding ribosomal RNA in mitochondria and chloroplasts matches corresponding bacterial DNA

Front 930

what forms a rung at the isthmus of dividing bacteria?

Back 930

FtsZ

Front 931

a plat cell (euk) has an inner membrane and an outer membrane, what is the function of these membranes?

Back 931

-the inner membrane: specialises in interactions with nucleoplasm (lamins-ntermediate filaments) and
-the outer membrane is continous in many palces with the cytoplasmic membrane, interacts with cytoplasm
the outer membrane has a protein layer that is associated with the nucleoplasm side of inner membrane, which helps maintain shape and help organise genetic material

Front 932

what joins the inner and outer euk cell membrane

Back 932

100nm pore join the inner and outer membranes

Front 933

can DNA and RNA pass though the euk membranes?

Back 933

yes, they are larger but thin, so they can pass through

Front 934

in euk cells, the nucleolus (not nucleus) is the site of

Back 934

Ribosomal RNA synthesis

Front 935

the Ribosomal subunits are assembled in the nucleolus, and transported to the cytoplasm to make

Back 935

Ribosomes

Front 936

genetic material is enclosed in a membrane bound structure called the

Back 936

nucleus

Front 937

the nucleus seperates

Back 937

DNA replication and RNA synthesis from protein synthesis (transcription, translation coupled proks)

Front 938

the nuclear membrane or envelope is a paired unit of membranes that is separated by a

Back 938

space of variable thickness (size varies from 5um in diameter)

Front 939

there are regions of some chromones having multiple copoes of rRNA genes called

Back 939

nuclear organisers

Front 940

nucleolus disappears during ________________ and reforms when __________________

Back 940

nucleolus disappears during nuclear division and reforms when division is complete

Front 941

eukaryotic cell has what kind of DNA

Back 941

DNA is liniar stored as chromosomes via histones

Front 942

human DNA is divided into ____liniar pieces of different size, most cells have two copies of chromosomes

Back 942

23 linear pieces

Front 943

the amount of DNA and chromosome number varies between

Back 943

organisms

Front 944

how many chromosomes does yeast have?

Back 944

17 chromosomes

Front 945

yeast has ____times the amount of DNA as E coli

Back 945

three times the amount (51)

Front 946

DNA in chromosomes are complexed with the basic positively charged proteins called

Back 946

histones

Front 947

DNA is ______charged

Back 947

negatively

Front 948

DNA is compacted by the

Back 948

winding around the core of 4 histones

Front 949

DNA is negatively charged, and if tried to compact dna without histones, the tendency would be for different parts of the DNA to

Back 949

repel eachother

Front 950

Histones are positivel charged (lots of Arg and Lys) which

Back 950

neutralise some negative charge (otherwise DNA would self repel)

Front 951

DNA plus histone strcuture is called a

Back 951

nucleosome

Front 952

DNA complexed with histones is called

Back 952

chromatin

Front 953

the fifth histone (H1) acts like

Back 953

a piece of tape preventing DNA from unwinding from the core

Front 954

the fifth histone (H1) is highly

Back 954

positively charged


main role in compacting DNA

Front 955

chromatin appears as 100A beads (nucleosomes) connected by thin fibres called

Back 955

linker DNA

Front 956

chromatin has equal amounts of

Back 956

DNA and histones

Front 957

when does chromatin fold further to give condensed chromosomes?

Back 957

at cell division

Front 958

describe key physiological and morphological features that would differentiate staphyloccocus from Micrococcus (18.1)

Back 958

lactic acid baceria include organisms such as Streptococcus, Lactobacillus, Staphylococcus, and many other. Homofermentatiive or heterofermentative metabolisms dominate the group, and some species are pathogens of humans and other animals

Front 959

What physiological features distinguish Bacillus from Clostridium (18.2)

Back 959

Production of endospores is a hallmark of the key genera Bacillus and Clostridium. Gram-positive bacteria are major agents for the degradation of organic matter in soil, and a few species are pathogenic

Front 960

what is the key feature that differentiates Mycobacterium from other gram positive bacteria such as Bacillus and Propionibacterium (18.4 and 18.5)

Back 960

Corynebacterium and ARthrobacter are common gram positive soil bacteria. Propionibacterium ferments lactate to propionate and is the key agent responbsile for the unique flavour and texture of swiss cheese

species of the genus Mycobacterium are mainly harmless soil saprophytes, but mycobacterium tunerculosis causes the disease tuberculosis. Cells of M.Tuberculosis have a lipid rich, waxy outer surface layer that requires special staining procedures (acid fast stain) in order to observe the cells micrscopically

Front 961

what is the most significant characteristic of Streptomyces (18.6)

Back 961

the streptomycetes are a large group of filamentous, gram positive bacteria that form sportes at the end of aerial filaments. many clinically usueful antibiotics such as tetracycline and neomycin ahve come from Streptomyces species

Front 962

what is a property of Mycobacterium species in which cells stained with the dye basic fuchsin resist decolorization with acidic alcohol?

Back 962

Acid-fastness

Front 963

what is a cigar shaped structure bounded by a non unit membrane and containing the light harvested bacteriochlorophyll in green sulfur bacteria and chloroflexus?

Back 963

chlorosome

Front 964

what is a two or more member association of bacteria, usually living in an intimate symbiotic fashion?

Back 964

Consortium

Front 965

what is in reference to lactic acid bacterial capable of making more than one fermentation product?

Back 965

heterofermentative

Front 966

what is in reference to lactic acid bacteria producing only lactic acid as a fermentation product?

Back 966

homofermentative

Front 967

what is a slender, tightly coiled gram negative bacteria characterized by possession of endoflagella used for motility?

Back 967

spirochete

Front 968

What is the name of the oval structure within the rod-shaped bacterial cell?

Back 968

Endospore

Front 969

An association of two specific types of bacteria where both members benefit is termed _

Back 969

a consortium

Front 970

Lactobacilli are important economic bacteria used in the production of

Back 970

yogurt

Front 971

The Mollicutes are distinguished by the

Back 971

absence of a cell wall

Front 972

Swiss cheese is made using

Back 972

propionic acid fermenting bacteria

Front 973

Tuberculosis is a disease caused by

Back 973

Mycobacterium tuberculosis

Front 974

The aerial filaments of the Streptomyces are called

Back 974

sporophores

Front 975

In cyanobacteria gas vesicles are used to regulate _________ in response to light intensity.

Back 975

buoyancy

Front 976

Which bacteria are found as common commensals of humans?

Back 976

Staphylococcus

Front 977

Lactobacillus is gram

Back 977

negative

Front 978

The Gram stain cannot be used to identify the mycoplasmas because _________.

Back 978

they do not have a cell wall

Front 979

Heterocysts are found in _________.

Back 979

cyanobacteria

Front 980

A unique bacterial group whose cells show extensive compartmentalization is __________.

Back 980

the Planctomycetes

Front 981

A thermophilic bacterium that produces commercially useful amylase, cellulose, and xylanase is _________.

Back 981

Rhodothermus

Front 982

in eukaryotic cell cycle, cell division involves:

Back 982

-Cellgrowth
-duplication of chromosomes (DNA)
-Cytokinesis (formation of two daughter cells)

Front 983

the cell cycle involves which phases?

Back 983

G1, s, G2 and M phase

Front 984

in what phase does the growth nof the cell occur, RNA and protein synthesis but no DNA synthesis?

Back 984

G1 phase

Front 985

in what phase dois known as the DNA synthesis phase, where DNA in chromosomes are duplicated, and growth continues?

Back 985

S phase

Front 986

in what phase do cells continue growing and making preperations for division?

Back 986

G2 phase

Front 987

in what phase does mitosis occur after S phase, each chromosome consists of two sister chromatids held together by centromeres

Back 987

M phase

Front 988

the G1, S and G2 phasees are collectively known as

Back 988

interphase

Front 989

two sister chromatids are held together by

Back 989

centromeres

Front 990

sister chromatids are pulled apart and evenly redistributed to 23 nuclei one at each end of the cell during

Back 990

mitosis

Front 991

Mitosis is the division of the

Back 991

nucleaus

Front 992

division of cell in two follows immediately after mitosis and is called

Back 992

cytokinesis

Front 993

cytokinesis occurs in what kind of cells

Back 993

plant and animal

Front 994

cleavage furrow forms in

Back 994

animal cells

Front 995

a cell plate forms between

Back 995

daughter cells in plant cells

Front 996

mitosis and cell division leaves two daughter cells, each

Back 996

genetically idrentical to the mother (A sexual reproduction)

Front 997

cell division consist of three key events:

Back 997

-replication of the organisms genome (total cellular DNA)

-Division of the genome to the two daughter cells

-Division of the body of the cell and partitioning of the non DNA components

Front 998

in a non dividing cell the DNA is present in a relaxed state knwon as

Back 998

chromatin

Front 999

chromatin is relaxed so that different genes expressed by the cell are

Back 999

easily accessed and read (transcribed)

Front 1000

just before cell division the DNA is

Back 1000

replicated (identical ciopy is produced)

Front 1001

after replication the DNA then condenses into tightly coiled structures called

Back 1001

chromosomes held together by proteins

Front 1002

replicated chromosomes are joined at first and are called

Back 1002

sister chromatids

Front 1003

normal cell division involves what two phases?

Back 1003

-Mitosis and Cytokinesis

Front 1004

division of the nucleus and duplicated chromosomes are an example of

Back 1004

mitosis

Front 1005

division of the cytoplasm is knwon as

Back 1005

cytokinesis

Front 1006

in what cell cycle phase does DNA synthesis occur where DNA is copied, and chromosomes are duplicated?

Back 1006

S phase

Front 1007

in what cell cycle phase are the cells growing, proteins and organelles are synthesized

Back 1007

first Gap (G 1)

Front 1008

in what cell cycle phase does further growth and preparation for division occur?

Back 1008

second Gap (G2 phase)

Front 1009

in what cell cycle phase does cell division occur?

Back 1009

M phase

Front 1010

the combination of Mitosis and Cytokinesis produces

Back 1010

two identical duaghter cells

Front 1011

the cell cycle consists of a long interphase, of growth and DNA synthesis followed by

Back 1011

mitosis

Front 1012

which scientist discovered a specific class of genes that control the cell cycle, one was called start, which was found to have a central role in controlling the fist step of each cell cycle, he also introduced the concept "Checkpoint" ?

Back 1012

Leland Hartwell

Front 1013

what kind of bacteria did Leland Hartwell do his experiments on to discover the genes and concept of checkpoint?

Back 1013

Saccharomyces cerevisiae (Bakers yeast)

Front 1014

what bacteria did Paul nurse and then later Timothy Hunt (awarded nobel prize) identify one of the key regulators of the cell cycle CDK (Cyclin dependent kinase) showing the function of the CDK was highly conserved during evolution

Back 1014

Budding yeast-Schizosaccharomyces pombe

Front 1015

what is the function of CDK (cyclin dependent kinase)

Back 1015

it drives the cell through the cell cycle by chemical modification (Phosphorylation) of other proteins

Front 1016

what drives a cell from one phase to the next in the cell cycle?

Back 1016

CDK molecules and Cyclins

Front 1017

cell division is controlled by

Back 1017

checkpoints/barriers

Front 1018

to pass the checkppoits/barriers in a cell cycle, the cell requires a

Back 1018

"go ahead" signal often a growth factor

Front 1019

which checkpoint is common, where newve cells and muscle cells are mostly stuck their

Back 1019

the G1 phase (Gap 1 phase)

Front 1020

increased levels of CDK molecules and cyclins are sometimes found in

Back 1020

human tumours, such as breast cancer and brain tumours

Front 1021

what cell has conjugation, a type of sex?

Back 1021

prokaryotes

Front 1022

eukaryotic microbes exhibit sexual reproduction analogous (different) to that for

Back 1022

plants and animals

Front 1023

eukaryotic microbes exhibit sexual reproduction analogous (different) to that for plants and animals, where by the exhibit two cells (gametes) that fuse to form a

Back 1023

single cell (zygote)

Front 1024

cells that fuse (sperm and egg cells) are

Back 1024

haploid, one copy of each chromosome, all copies from one parant

Front 1025

when haploid cells fuse, the number of chromosomes are

Back 1025

doubled

Front 1026

the extent of haploid and diploid phases in euk microorganisms varies, but yeast

Back 1026

can remain indefinitely in n or 2n state

Front 1027

movement in eukaryotic cmicroorganisms involves both

Back 1027

cytoplasmic streaming and
motility

Front 1028

cytoplasmic streaming is the flow of

Back 1028

cytoplasm around the cell interior, speeds distribution of materials within the cell (2->1000 um/sec)

Front 1029

Motility is where the cell

Back 1029

moves itself through the medium

Front 1030

an example of euk motility is where eukaryotes use

Back 1030

flagella (cilia) in propulsion

Front 1031

amoeboid movement is also common in

Back 1031

amoebae and macrophages

Front 1032

cilia is found most frequently in one group of protozoa called the

Back 1032

ciliates

Front 1033

ciliates have ____________cilia per cell

Back 1033

10000-14000

Front 1034

in ciliates, groups (patches) of cilia beat to make a

Back 1034

coordinates wave of ciliary movement along the cell

Front 1035

eukaryotic flagellum undulates setting up a

Back 1035

wave like motion

Front 1036

in prokaryotic, flagellum

Back 1036

rotates (very different and unrelated type of motion)

Front 1037

what causes a wave like motion to be directed away from the cell?

Back 1037

a force generated away from the cell results in a pushing action, seen in animal sperm cells, dinoflagellates (algae)

Front 1038

what causes a wave to be directed towards the cells?

Back 1038

force directed towards the cell resulting in a pulling action (seen in trypanosomes)

Front 1039

cilia work more like oars, since they have

Back 1039

alternativing power and recovery strokes (10-30 strokes per minute)

Front 1040

ciliated microorganisms are faster than

Back 1040

flagellated ones

Front 1041

flagella and ciliar share what common structure?

Back 1041

a core of microtubules covered by a sheath, made of straight hollow rods

Front 1042

the core of microtubules covered by a sheath is contructed of proteins called

Back 1042

tubulins

Front 1043

the core of microtubules has

Back 1043

peripheral ring of 9 doublet microtubule fibres

Front 1044

in the core of microtubules covered by sheat, the side arms coming off one end of the doublet fibre is made of a protein called

Back 1044

dynein

Front 1045

in the centre of the ring are

Back 1045

2mts, (9+2 arrangement) of microtubules

Front 1046

doublets of outer ring are connected to central microtubules by

Back 1046

radial spokes

Front 1047

microtubule assembly is anchored in the cell by a

Back 1047

basal body

Front 1048

basal body has a ring of

Back 1048

9 triplet microtubule fibres

Front 1049

what is a molecule motor/ATP is hydrolyzed

Back 1049

dynein

Front 1050

dyneins side arms of 1 doublet attach to

Back 1050

adjacent doublet and pull, so two microtubules slide past each other in opposite direction

Front 1051

what prevents microtubules from sliding past each other very far?

Back 1051

radial spokes restrein microtubules

Front 1052

because they are anchored, the microtubules of the aconeme

Back 1052

bend

Front 1053

the change in pulling pattern along length of microtubule, and alteration in when pulling occurs where along length of flagellum, results in a

Back 1053

wave like movement