Bisc 260 - Exam 1 (Ch. 1-4)

Front 1

Van Leeuwenhoek

Back 1

first person to observe and describe microorganisms accurately; "animalcules"

Front 2

Koch

Back 2

Establish the link between a particular microorganism and a particular disease

Front 3

Lister

Back 3

Surgical sanitation

Front 4

Pasteur

Back 4

Considered the father of modern microbiology.
Demonstrated that air is filled with microorganisms; swan neck experiment

Front 5

Redi

Back 5

Maggots come from flies

Front 6

Tyndall

Back 6

demonstrated that dust carries microorganisms; showed that if dust was absent, broths remained sterile, even if directly exposed to air

Front 7

What are the three domains of life and which contain microorganisms?

Back 7

Bacteria : True Bacteria.
Archaea.
Eukarya: Protists (algae, protozoa, slime molds, and water molds) and fungi (yeast and mold).

Front 8

What organism evolved first?

Back 8

Bacteria/Prokaryotes

Front 9

What is the human microbiome project?

Back 9

*Determine whether or not all humans have the same microorganisms inside of them
*Determine whether or not changes in the microbiome affect overall health
*Developing tools to research these goals
*Address legal and ethical concerns

Front 10

What are some of the beneficial products made by microorganisms?

Back 10

-Ethanol
-Dietary amino acids
-Pesticides (Bt Bacillus thuringiensis)
-Antibiotics from soil bacteria: Streptomyces and Bacillus

Front 11

Woes

Back 11

Three domains, rather than five kingdoms

Front 12

Bacteria VS Archaea

Back 12

Archaea: cell membrane contains ether linkages; cell wall lacks peptidoglycan; genes and enzymes behave more like Eukaryotes; have three RNA polymerases like eukaryotes; and extremophiles

Bacteria: cell membrane contains ester bonds; cell wall made of peptidoglycan; have only one RNA polymerase; react to antibiotics in a different way than archea do.

Front 13

Explain the “RNA world hypothesis” (Fig. 1.7). What discoveries led them to propose this hypothesis?

Back 13

RNA is said to work both as an enzyme and as a container of genes. Life was built on RNA before DNA, RNA and proteins.

Front 14

Koch’s postulates: when is it used, what are the steps, when does it not work?

Back 14

Establish the link between a particular microorganism and a particular disease.
Steps: Suspected organism is removed and grown. Check if animal is healthy. If it is, reintroduce the organism. See if animal is sick. Repeat.
Doesn't work if:
Microorganisms that are unable to be cultured. When 2 or more organism work in synergy to cause a disease.  Ethical exceptions. Highly contagious.

Front 15

Will not grow in pure cultures

Back 15

Rickettsias, Chlamydias, and Viruses

Front 16

Refractive Index

Back 16

a measure of how greatly a substance slows the velocity of light

Front 17

short focal length = more magnification
shorter wavelength = greater resolution

Back 17

Okay cool.

Front 18

Bright-Field Microscopy

Back 18

the type of microscope: Bright Field
what is used for illumination: Visible Light
what is the limit of magnification: 100x
limit of resolution: 2 micrograms
what is the sample placed on: Slide
state of sample: Alive or dead
source of contrast: Staining
what would the image look like (flat, 3D, color, etc.): Bright background, dark specimen

Front 19

Fluorescence Microscopy

Back 19

the type of microscope: Flourescent
what is used for illumination: UV
what is the limit of magnification: ?
limit of resolution: ?
what is the sample placed on: Slide?
state of sample: Alive (Green) or dead (red)
source of contrast: Fluorescent dyes (fluorochromes)
what would the image look like (flat, 3D, color, etc.): Flat fluorescent image; black background, bright-stained specimen

Front 20

TEM

Back 20

the type of microscope: TEM
what is used for illumination: Electron Beam
what is the limit of magnification: 5,000,000 x
limit of resolution: .5 nm
what is the sample placed on: Metal Grid
state of sample: Dead
source of contrast: Scattering of electrons
what would the image look like (flat, 3D, color, etc.): Flat, black and white.

Front 21

SEM

Back 21

the type of microscope: SEM
what is used for illumination:
what is the limit of magnification: 500,000 x
limit of resolution: .5 nm
what is the sample placed on: Metal Grid
state of sample: Dead
source of contrast: Scattering of electrons
what would the image look like (flat, 3D, color, etc.): 3D, black and white

Front 22

Parfocal lens

Back 22

A lens that stays in focus when magnification/focal length is changed.

Front 23

Differential stain

Back 23

Heat fixed mixture, crystal violet, iodole, alcohol, safranin. Gram negative and positive are different colors

Front 24

Simple Stain

Back 24

Heat fixed bacteria, stained, add crystal violet

Front 25

Plasma membrane

Back 25

Function: Separates cell from its environment, selectively permeable membrane,
Type: Prokaryote
Structure:

Front 26

Fluid mosaic model

Back 26

Function: that membranes are lipid bilayers within which proteins float.
Type: Prokaryotes
Structure: Lipid bilayer

Front 27

Cell wall

Back 27

Function: Protects from osmotic lysis, shapes cell
Type: Bacteria
Structure: Rigid structure that is outside of the plasma membrane

Front 28

Peptidoglycan (Fig. 3.11-3.13)

Back 28

Function:
Type:
Structure: meshlike polymer of identical subunits forming long strands. Crosslinked by peptides

Front 29

Pseudomurein

Back 29

Function: Exactly like Peptidoglycan
Type: Archaea
Structure: Similar to Peptidoglycan

Front 30

Hopanoids

Back 30

Function: Stabilize bacterial membranes
Type: Bacteria
Structure: Steroid

Front 31

Cholesterol

Back 31

Function: Steroid, Contributes to membrane strength
Type: Eukaryotes
Structure: Steroid

Front 32

Peptide interbridge

Back 32

Function: Strengthens peptidoglycan
Type: Prokaryotes
Structure:

Front 33

LPS (three parts)

Back 33

Function: lipid A - helps stabilize outer membrane structure, can act as an toxin
core polysaccharide - contributes to negative charge on cell surface
O side chain (O antigen) - protection from host defenses
Type: Prokaryotic
Structure:

Front 34

Teichoic acids

Back 34

Function: give wall negative charge
Type: Prokaryotes
Structure:

Front 35

Periplasm

Back 35

Function: buffer between the external environment and the inside of the bacterium
Type: Bacteria
Structure:

Front 36

Outer membrane

Back 36

Function:
Type:
Structure: lies outside the thin peptidoglycan layer

Front 37

Braun’s lipoproteins

Back 37

Function: connect outer membrane to peptidoglycan
Type:
Structure:

Front 38

Protoplast

Back 38

Function: is plasma membrane and everything within
Type: Bacteria
Structure:

Front 39

Capsule/slime layer

Back 39

Function: Capsule: usually composed of polysaccharides
well organized and not easily removed from cell; Slime layers: similar to capsules except diffuse, unorganized and easily removed
Type:
Structure:

Front 40

S-layer

Back 40

Function: regularly structured layers of protein or glycoprotein
In bacteria the S layer is external to the cell wall
common among Archaea, where they may be the only structure outside the plasma membrane
Type:
Structure:

Front 41

Cytoskeleton (prokaryotic) FtsZ & MreB

Back 41

Function: vast network of interconnected filaments within the cytoplasmic matrix
filaments that form the cytoskeleton: microfilaments (actin), microtubules, intermediate filaments, plays role in both cell shape and cell movement

homologs of all 3 eukaryotic cytoskeletal elements have been identified in bacteria and 2 in archaea
functions are similar as in eukaryotes
Role in cell division, protein localization, and determination of cell shape


FtsZ (tubulin)– many bacteria and archaea
forms ring during septum formation in cell division

MreB (actin) – many rods, some archaea
maintains shape by positioning peptidoglycan synthesis machinery

Front 42

Inclusion bodies

Back 42

granules of organic or inorganic material that are stockpiled by the cell for future use

Front 43

Ribosomes

Back 43

80S in size
60S + 40S subunits = eukaryotic ribosomes
70S = Prokaryotic ribosomes

Front 44

nucleoid

Back 44

Procaryotic chromosomes are located in the nucleoid
Haploid
Very tightly coiled

Front 45

Chromosome

Back 45

a closed circular (typically), double-stranded DNA molecule
looped and coiled extensively
nucleoid proteins probably aid in folding

Front 46

Plasmid

Back 46

may exist in many copies in cell
classification of plasmids based on mode of existence, spread, and function

Front 47

Pili/fimbrae

Back 47

fimbriae (s., fimbria)
short, thin, hairlike, proteinaceous appendages
up to 1,000/cell
mediate attachment to surfaces
some required for twitching motility or gliding motility that occurs in some bacteria

sex pili (s., pilus)
similar to fimbriae except longer, thicker, and less numerous (1-10/cell)
required for mating

Front 48

Flagella (parts and basic assembly)

Back 48

Filament
Extends to exterior
Made of proteins called flagellin

Hook
Connects filament to cell

Basal body
Anchors flagellum into cell wall
series of rings that drive flagellar motor

Front 49

Mitochondria

Back 49

Function:
Type:
Structure:

Front 50

Bacterial spores

Back 50

Function:
Type:
Structure:

Front 51

Sporulation/germination

Back 51

Function:
Type:
Structure:

Front 52

Nucleus

Back 52

Function:
Type:
Structure:

Front 53

Endocytosis

Back 53

Function:
Type:
Structure:

Front 54

ER (rough and smooth)

Back 54

Function:
Type:
Structure:

Front 55

Golgi

Back 55

Function:
Type:
Structure:

Front 56

Lysozomes

Back 56

Function:
Type:
Structure:

Front 57

Ubiquitin

Back 57

Ubiquitin tags can also direct proteins to other locations in the cell, where they control other protein and cell mechanisms.
Eukaryotes

Front 58

What is peptidoglycan made out of? What gives it its extra strength?

Back 58

Sugars and amino acids; Crosslinked peptides

Front 59

What are the basic shapes of microorganisms?

Back 59

Cocci, rod, vibrio (comma shaped), spirillium (spiral), spirochete (helix)

Front 60

What is the difference between the Gram + and Gram - cell wall structures?

Back 60

Gram positive: appear- blue to transfer to purple
Structure: Have thick layer of peptidoglycan over inner cytoplasmic membrane. Lack LPS-lipopolysaccharides

Gram negative:
appear: pink to transfer to red
Structure: the peptidoglycan layer is thinner and is located between space of the outer and inner cytoplasmic membrane.
cell wall contains LPS which make them virulent

Front 61

What produces the negative charge of the cell wall in G- & G+?

Back 61

Techoic acids

Front 62

What is chemotaxis? (fig. 3.49 and 3.50)

Back 62

Bacteria use flagella to detect nearby chemicals and run and tumble toward or away from them

Front 63

Compare and contrast Bacteria and eukaryotic cells. Please list 3 differences between eukaryotic cells and Bacterial cells. Then list 3 structures or properties they have in common.

Back 63

1) Eukaryotes contain membrane-bound organelles; bacteria do not.
2) Eukaryotic DNA is circular; bacterial DNA is linear
3) Eukaryotic DNA has a complex of histones; bacteria does not.
4) The ribosomes of eukaryotic cells are larger and more complex than those of bacteria.
5) Eukaryotes contain a nucleus; the DNA in bacteria is concentrated in a nucleoid region with no membrane.
6) In Eukaryotes, transcription and translation are distinct processes, whereas in bacteria, the two occur simultaneously.
7) Eukaryotic cells comprise multicellular organisms, whereas bacteria are usually single-celled organisms.

Front 64

Explain the endosymbiotic hypothesis. What features of mitochondria and chloroplasts support the endosymbiotic hypothesis of eukaryotic cells?

Back 64

Endosymbiont theory is the idea that eukaryote cells arose in evolution by the fusion of previously free-living protists;
1) Both have two cell membranes
2) Similar ribosomes
3) Unique DNA

Front 65

monotrichous

Back 65

one flagellum

Front 66

Polar flagellum

Back 66

flagellum at end of cell

Front 67

amphitrichous

Back 67

one flagellum at each end of cell

Front 68

lophotrichous

Back 68

cluster of flagella at one or both ends

Front 69

peritrichous

Back 69

spread over entire surface of cell