Micro Exam 1

Front 1

Microbiology

Back 1

The study of Microbes

Front 2

Microbes

Back 2

organisms so small that a microscope is needed to study them

Front 3

Cells

Back 3

the basic unit of structure and function in living things

Front 4

Viruses

Back 4

a submicroscopic , parasitic, acellular organism composed of nucleic acid (DNA or RNA) core inside a protein coat

Front 5

Bacteria

Back 5

single-celled organisms with a spherical, rod, or spiral shapes but a few form filiment althought cellular, they HAVE NO NUCLEUS and they lack a membrane enclosed structure.

Front 6

cellular

Back 6

can live alone

Front 7

acellular

Back 7

not consisting of , diving into or containing cells

Front 8

prokaryotic

Back 8

don't have a nucleus

Front 9

eukaryotic

Back 9

have a nucleus

Front 10

Archaea

Back 10

are prokaryotic and cellular

Front 11

Bacteria

Back 11

are prokaryotic and cellular

Front 12

Algae

Back 12

eukaryotic and cellular

Front 13

Fungi

Back 13

are eukaryotic and cellular

Front 14

Protozoa

Back 14

eukaryotic and cellular

Front 15

Various species are involved in fermentation, putrefication, infectious disease or nitrogen fixation

Back 15

bacteria

Front 16

Algea

Back 16

any of a numerous group of chlorophill containing, mainly aquatic, eukaryotic organisms ranging from microscopic single celled forms to multicellular forms.

Front 17

these are distinguished from plants by the abcence os the true roots, stems, leaves and lack of non reproductive cells in the reproductive structure

Back 17

algea

Front 18

Fungi

Back 18

a diverse group of eukaryotic single celled organisms that live by decomposing and obsorbing organic materials in which they grow, comprising the mushroom, molds, mildews, smuts, rusts and yeast

Front 19

Robert Hooke

Back 19

reported that living things were composed of little boxes or cells

Front 20

Leeuwenhoek

Back 20

1st to see living organisms through a microscope

Front 21

Spontaneous generation

Back 21

the hypothesis that living organisms arise from nonliving matter; a vital force forms life

Front 22

Biogenesis

Back 22

the hypothesis that the living organism arise from preexisting life

Front 23

Pasteur

Back 23

The father of microbiology, developed techniques to weaken an organism so they will product immunity without producing disease

Front 24

Pasteurization

Back 24

The application of a high heat for a short time

Front 25

cell theory

Back 25

that cells are the fundamental units of life and carry out all the basic functions of living things

This still applies today to all cellular organisms except bacteria

Front 26

Koch's Postulate

Back 26

provided a method of establishing the germ theory of disease

1) the specific causative agent must be found in every case of the disease

2) The disease organism must be isolated in pure culture

3) Inoculation of a sample if the culture into a healthy, susceptable animal must produce the same disease

4) The disease organism must be recovered from the innoculated animal.

Front 27

Liser

Back 27

proved and created the 1st aseptic techniques in order to prevent the spread of infection

Front 28

Chemotherapy

Back 28

treatment with chemicals

Front 29

Cheotherapeutic agents used to treat infectious disease can be _______________ or ___________

Back 29

synthetic agents , antibiotics

Front 30

antibiotics

Back 30

chemicals produced by bacteria and fungi that inhibit or kill other microbes

Front 31

antibodies

Back 31

molecules the body immune system produces to combat invading microbes and their toxic products.

Front 32

bacteriophages

Back 32

(also called a phage) the future of microbiology. The viruses that attack and kill specific kinds of bacteria

Front 33

Jenner

Back 33

used fluid from cowpox blisters to immunize against "smallpox", thus creating the 1st immunization

Front 34

Human genome project

Back 34

microbial genetic techniques have made possible a colossal scientific undertaking to identify the location and chemical sequence of all the genes in the human genome

Front 35

Bacteriophage Therapy

Back 35

is the therapeutic use of bacteriophages to treat pathogenic bacterial infections

Front 36

Genomics

Back 36

is a discipline in genetics that applies recombinant DNA, DNA sequencing methods, and bioinformatics to sequence, assemble, and analyze the function and structure of genomes (the complete set of DNA within a single cell of an organism).

Front 37

viroid

Back 37

an infectious RNA partical smaller than a virus and lacking a capsid, that causes various plant diseases

Front 38

Prion

Back 38

an exceedingly small infectious particle of protein without any nucleic acid

Front 39

domain

Back 39

a new taxonomic category above the kingdom level , consisting of the Archaea, bacteria and eukarya

Front 40

microbe

Back 40

organisms studies with a microscope , including viruses

Front 41

Chemistry

Back 41

the study of interactions between atoms and molecules

Front 42

Atom

Back 42

the smallest unit of matter that enters into a chemical reaction

Front 43

when two or more atoms combine chemically, they form ____________

Back 43

molecules

Front 44

Molecules made up of atoms of 2 or more elements are called _________________

Back 44

compounds

Front 45

Subatomic particles

Back 45

protons, neutrons and electrons

Front 46

electrons have a _________ charge

Back 46

negative

Front 47

protons have a _________ charge

Back 47

positive

Front 48

neutrons have a ________ charge

Back 48

neutral

Front 49

atoms normally have _____________ number of electrons and protons

Back 49

equal

Front 50

atoms are normally considered to be electrically ___________

Back 50

neutral

Front 51

The protons and neutrons can be found in the _______________

Back 51

nucleus

Front 52

matter composed of one kind of atom is called an ____________

Back 52

element

Front 53

The atoms of a particular element always have the same # of protons and that # of protons is also the ____________

Back 53

atomic number

Front 54

Electrons with the ____________ amount of energy are found nearest the nucleus

Back 54

least

Front 55

Rule of the octets

Back 55

a chemical rule of thumb that reflects observation that atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.

Front 56

ion

Back 56

a charged atom produced when an atom gains or loses one or more elctrons

Front 57

anion

Back 57

a negatively charged ion ~ an atom that gains an electron to fill its outer shell

Front 58

cation

Back 58

a positively charged ion ~ when an atom loses one if its electrons in the outer shell without also losing a proton

Front 59

when an outer shell is full it is said to be more ______________

Back 59

stable

Front 60

The sum of the # of protons and neutrons in an atom is the ________

Back 60

atomic #

Front 61

Isotope

Back 61

Atoms of a particular element that contain a different # of neutrons.

Front 62

a __________ or _________ is the weight of a substance in grams equal to the sum of the atomic weight of the atoms in a molecule of the substance.

Back 62

a gram molecular weight , mole

Front 63

__________ form between atoms through the interactions of electrons in their outer shell. Energy associated with these bonding electrons hold the atoms together, forming molecules

Back 63

chemical bonds

Front 64

Ionic bonds

Back 64

result from the attraction between the ions that have opposite charges. This type of bond occurs when there is complete transfer (between the two atoms) of the electrons in the bond. (+) + (-) = ionic bond

The rule is that when the electronegativity difference is greater than 2.0, the bond is considered ionic.

Front 65

covalent bond

Back 65

instead of gaining and losing electrons, as in ionic bonding, carson and some other atoms share pairs of electrons.

Front 66

equal sharing of electrons produces _____ which are compounds with no charged regions. This type of bond occurs when there is equal sharing (between the two atoms) of the electrons in the bond. Molecules such as Cl2, H2 and F2 are the usual examples.

Back 66

nonpolar compunds

Front 67

Hydrogen bond

Back 67

Interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons; such a bond is weaker than an ionic bond or covalent bond but stronger than van der Waals forces. These exist between atoms in different molecules or in parts of the same molecule. One atom of the pair (the donor), generally a fluorine, nitrogen, oroxygen atom, is covalently bonded to a hydrogen atom (−FH, −NH, or −OH), whose electrons it shares unequally; its high electron affinity causes the hydrogen to take on a slight positive charge.

Front 68

Polar bond

Back 68

This type of bond occurs when there is unequal sharing (between the two atoms) of the electrons in the bond. Molecules such as NH3 and H2O are the usual examples.

Front 69

during __________ the breakdown of substances, food is degraded and some of that stored energy is released. Microorganisms use nutrients in the same general way

Back 69

catabolism

Front 70

Catabolic reactions are considered to be _________ ~ that is they release energy

Back 70

exergonic

Front 71

_________ is the buildup or synthesis of substances, energy is used to create bonds

Back 71

anabolism

Front 72

most anabolic reactions are said to be ___________ ~ that is they require energy

Back 72

endergonic

Front 73

a dissolving medium

Back 73

solvent

Front 74

water is a ________

Back 74

solvent

Front 75

water is a ________ molecule

Back 75

polar

Front 76

the ___________ region around the water molecule is attracted to the __________ ions and the _____________ region of the water molecule is attracted to the ________ ions allowing them to distribute evenly.

Back 76

positive, negative, negative, positive,

Front 77

a phenomenon in which the surface of water acts as a thin, invisible, elastic membrane. The polarity of the water gives them a strong attraction for one another but no attraction for gas molecules in air at the water's surface. Therefore the water molecules cling together, forming hydrogen bonds with another molecule below the surface

Back 77

surface tension

Front 78

In living cells, __________ allows a thin film of water to cover the membranes and to keep them moist.

Back 78

surface tension

Front 79

In an anabolic reaction, the components of water (H+ and OH-) are removed front the reactants to form a larger product molecule

X--H + HO--Y --> X--Y + H2O

This kind of reaction is called a _____________ reaction

Back 79

dehydration

Front 80

The _____________ reaction is involved in the synthesis of complex carbohydrates, some lipids (fats) and proteins

Back 80

dehydration

Front 81

The _______ reaction occurs in many catabolic reactions where water is added to a reactant to form simple products

X--Y + H2O --> X--H + HO---Y

Back 81

Hydrolysis

Front 82

_______reactions occur in the breakdown of large nutrient molecules to release simple sugars, fatty acids, and amino acids.

Back 82

Hydrolysis

Front 83

mixture

Back 83

2 or more substances that are combined in any proportion and are not chemically bound. ie: sugar and salt

Front 84

solution

Back 84

a mixture of 2 more more substances in which the molecules of the substances are evenly distributed and ordinarily will NOT separate out upon standing.

Front 85

In a solution the medium in which the substances are dissolved is the _________

Back 85

solvent

Front 86

The substance dissolved in the solvent is the ____________

Back 86

solute

Front 87

____________ can consist of atoms, ions and molecules

Back 87

solutes

Front 88

particles too large to form true solutions can sometimes form _______________

Back 88

colloids

Front 89

_________________ is cells usually are formed from large protein molecules dispersing in water

Back 89

colloidal dispersions

Front 90

alkaline

Back 90

basic

Front 91

Acid

Back 91

a hydrogen ion (H+) donor, donating the H+ to a solution

Front 92

HCL --> H+ + Cl-

Back 92

acid

Front 93

-CooH

Back 93

Carboxyl group

Front 94

a proton acceptor, or a hydroxyl ion donor, accepting H+ from or donating OH- (Hydroxyl ion)to the solution

Back 94

base

Front 95

The bases in living organisms are usually _______

Back 95

weak

Front 96

the acids in living organisms are usually _____

Back 96

weak

Front 97

__________ is what chemists devised to specify the acidity or alkalinity of a solution

Back 97

PH scale

Front 98

the __________ relates proton concentration to ph in a logarithmic scale, meaning the concentration of hydrogen ions (protons) change by the factor of 10 for each unit of scale.

Back 98

pH scale

Front 99

A pH of 7 is considered to be __________

Back 99

neutral

Front 100

Increasing H+ increases _______________

Back 100

acidity

Front 101

Increasing OH- increases _____________

Back 101

alkalinity

Front 102

pH of 2

Back 102

acidic

Front 103

pH of 12

Back 103

basic

Front 104

most organisms grow best between pH of _____ and ______

Back 104

6.5 and 8.5

Front 105

pH =

Back 105

-log(H+)

Front 106

pure water is acidic, neutral or basic

Back 106

neutral

Front 107

growth of fungi usually occurs between the pH of ____ and _____

Back 107

5 and 9

Front 108

The basic study of chemistry which is the study of compounds that contain carbon

Back 108

organic chemistry

Front 109

the study of chemical reactions that occur in living systems is known as ____________

Back 109

biochemistry

Front 110

functional group

Back 110

a part of a molecule that generally participates in chemical reactions as a unit and that give the molecule some of its chemical properties

Front 111

the chain of carbon atoms in an organic molecule is the ______________

Back 111

carbon skeleton

Front 112

group that contains NH2

Back 112

amino

Front 113

the ________ group is responsible for protein formation

Back 113

amino

Front 114

group that contains SH

Back 114

sulfhydride

Front 115

the ______ group is responsible for the production of energy metabolism and protein structure

Back 115

sulfahydride

Front 116

group that contains -COOH

Back 116

carboxyl

Front 117

the __________ group is responsible for production of organic acids , lipids and proteins

Back 117

carboxyl

Front 118

group that contains -OH

Back 118

hydroxyl group

Front 119

group that contains PO4

Back 119

phosphate

Front 120

the __________ group is responsible for production of ATP , DNA

Back 120

phosphate

Front 121

oxidation

Back 121

the addition of oxygen or removal of hydrogen or electrons from a substance. ie: burning

Front 122

reduction

Back 122

the removal of oxygen or the addition of hydrogen or electrons to a substance

Front 123

macromolecule

Back 123

polymers consisting of many small repeating molecules

Front 124

the smaller molecules are called ___________

Back 124

monomers

Front 125

carbohydrates

Back 125

serve as the main source of energy for all living things

Front 126

plants make a structural carbohydrate in the form of________

Back 126

cellulose

Front 127

plants make a energy storage carbohydrate in the form of________

Back 127

starch

Front 128

animals, including humans, store energy in carbohydrates called _________

Back 128

glycogen

Front 129

all carbohydrates contain the elements _________, ________ and ____________

Back 129

carbon, hydrogen and oxygen

Front 130

There is normally a proportion of _____ hydrogen to each ___ carbon and _____ oxygen

Back 130

2,1,1

Front 131

monosaccharides

Back 131

a simple sugar with 3 to 7 carbon atoms.

Front 132

glucose and fructose are part of which carbohydrate group?

Back 132

monosaccharides

Front 133

isomer

Back 133

monosaccharides that have the same molecular formula but different structures and different properties

Front 134

The most abundant monosaccharide

Back 134

glucose

Front 135

a sugar & alcohol linkage

Back 135

glycosidic bond

Front 136

disaccharide

Back 136

formed when 2 monosaccharids are connected by the removal of water and the formation of glycosidic bond.

Front 137

a common disaccharide

Back 137

table sugar ~ made of glucose and fructose

Front 138

long chains of repeating units of glucose

Back 138

polymers

Front 139

_______________ consist of 10s to 100s of monosaccharides joined through dehydration synthesis

Back 139

polysaccharides

Front 140

_________ serves as a way to store energy and cellulose in a structural component of the cell wall

Back 140

starch

Front 141

oligosaccharides

Back 141

___________ contain 2 - 20 monosaccharides

Front 142

chitin

Back 142

___________ is a polymer of 2 sugars repeating many times

Front 143

________ constitute a chemically diverse group of substances that include fats, phospholipids, and sterioids

Back 143

lipids

Front 144

_______ are relatively insoluble in water but ate soluble in nonpolar solvents such as ether and benzene

Back 144

lipids

Front 145

___________ form part of the structure of cells, especially cell membrains and many can be used for energy

Back 145

lipids

Front 146

fats

Back 146

contain the 3-carbon alcohol glycerol and one or more fatty acids

Front 147

fatty acid

Back 147

consists of a long chain of carbon atoms with associated hydrogen atoms and a carboxyl group at one end of the chain

Front 148

triacylglycerol

Back 148

hydrogen rich lipid that release a large amount of energy

Front 149

saturated fat

Back 149

a simple lipid with no double bonds

Front 150

unsaturated fat

Back 150

a simple lipid with one or more double bonds in the fatty acid that has lost at least 2 hydrogens

Front 151

Cis formation of unsaturated fat

Back 151

H atom on the same side of the double bond

Front 152

Trans formation of unsaturated fats

Back 152

H atoms on opposite sides of the double bonds

Front 153

____________ are found in the cell membrane

Back 153

phospholipds

Front 154

steroids

Back 154

a 4-ring structure and quite different than other lipids. They include cholesterol, steroid hormones and vit. D

Front 155

among the molecules found in living things, _______ have the greatest diversity of structure and function.

Back 155

proteins

Front 156

_______ are components of eukaryotic membraine

Back 156

steroids

Front 157

________ are the building blocks of proteins

Back 157

amino acids

Front 158

_________ have at least one animo group (-NH2) and one acidic carboxyl group (-COOH)

Back 158

amino acids

Front 159

each amino acid is distinguishable by the different chemical group called the _________ that is attached to the central carbon.

Back 159

R group

Front 160

Polymers of amino acids are linked by their __________

Back 160

peptide bonds

Front 161

the ____________ structure of protein has a linear sequence of amino acids

Back 161

primary

Front 162

the _________ structure of a protein consists of the folding or coiling of the amino acid chains onto itself . EX: alpha helix or pleated sheets

Back 162

secondary

Front 163

the _________ structure of the protein produces further bending and folding into globular shapes and fibrous threadlike strands

Back 163

tertiary

Front 164

structural proteins

Back 164

contributes to the 3-D structure of the cell, cell parts and membranes

Front 165

enzymes

Back 165

are the protein catalysts and increase the rate at which chemical reactions take place within living organisms in the temperature range compatible with life

Front 166

catalyst

Back 166

the substance that controls the rate of chemical reaction in cells

Front 167

A ______________ is one of the structural components, or building blocks, of DNA and RNA

Back 167

nucleotide

Front 168

a ___________ consists of 3 parts

1) a nitrogen base

2) a 5-carbon sugar

3)one or more phosphate groups

Back 168

nucleotide

Front 169

The nucleotide _______ is the main source of energy in cells because it stores chemical energy in a form cells can use

Back 169

ATP

Front 170

Nucleic acids

Back 170

__________ consist of long polymers of neucleotides called pollyneucleotides

Front 171

_____________ contain all the genetic information that determines all the heritable characteristics of a living organism

Back 171

nucleic acid

Front 172

the 2 nucleic acids found in living organisms are ________ and _________

Back 172

RNA and DNA

Front 173

DNA

Back 173

stores genetic information, has double strands and is well defined

Front 174

DNA and RNA

Back 174

all cellular organisms have ________

Front 175

Viruses have

~ DNA

~RNA

~Neither

~Both

Back 175

DNA or RNA

Front 176

RNA

Back 176

carries information from the DNA to the sites where protein is being manufactured in cells

Front 177

The strands of proteins for in opposite direction in _______

Back 177

DNA

Front 178

Hydrophillic

Back 178

attracted to water

Front 179

hydrophobic

Back 179

repelled by water

Front 180

Polysaccharides

Back 180

found in plant cell walls, in the human liver, muscles and exoskeletons

Front 181

what type of bond is found between complementary nucleotides on 2 strands of DNA

Back 181

hydrogen bonds

Front 182

Adenine, Guanine, Cytosine, Thymine, and phosphoric acids are all found in _____

Back 182

DNA

Front 183

Is ribose found in DNA or RNA

Back 183

RNA

Front 184

Is deoxyribose found in DNA or RNA

Back 184

DNA

Front 185

Is Uracil found in DNA or RNA

Back 185

RNA

Front 186

In __________ thymine is replaced by Uracil

Back 186

RNA

Front 187

most bacteria can be seen at ________

Back 187

1-10 macrometers

Front 188

reflection

Back 188

bounces off the sample

Front 189

transmission

Back 189

can go THROUGH the specimin

Front 190

Absorption

Back 190

Is changed by simple direction change

Front 191

diffraction

Back 191

when rays of light are bent

Front 192

resolution

Back 192

the ability to see 2 separate items as separate and discrete units

Front 193

refraction

Back 193

the bending of the light as it passes from one medium to another of different density

Front 194

what kind of field is good for seeing things like spirokeets or other difficult to see organisms

Back 194

dark field

Front 195

(TEM) or transmission

Back 195

go through the sample like a cutting a slice to see the inside

Front 196

scanning (SEM)

Back 196

touches the surface, allowing you to see the surface but not inside

Front 197

digital microscopy

Back 197

allows to build a 3D image , usually a thick sample allowing the computer to break down each layer

Front 198

simple stain

Back 198

uses a single dye to reveal basic cell shape, and cell arrangement

Front 199

differential stain

Back 199

makes use of 2 or more dyes and destinguishes between 2 kinds of organisms or between 2 parts of the organism

Front 200

Gram stain is a ___________ stain

Back 200

differential

Front 201

acid-fast is a ______ stain

Back 201

differential

Front 202

The color of the gram stain is determined by the cell's ____________

Back 202

envelope

Front 203

mordant

Back 203

a chemical that helps retain the stain in certain cell walls

Front 204

in a gram stain a gram _______ organism remains purple

Back 204

positive

Front 205

in a gram stain a gram ______ organism show as pink

Back 205

negative

Front 206

in a gram stain, the __________ disolves the membrane and will decolorize the organism that is gram negative

Back 206

alchohol

Front 207

Ziehl-Neelson acid fast stains are used to identify ____________

Back 207

mycrobacterium such as TB

Front 208

negative staining

Back 208

___________ is used when specimen or part of it, such as the capsule, that resists taking up a stain

Front 209

Prokaryote

Back 209

____________ lack a nucleus and other membrane enclosed stuctures

Front 210

all bacteria are ___________

Back 210

prokaryotic

Front 211

eukaryotic

Back 211

cells that have a nucleus and membrane enclosed structures

Front 212

all plants, animals, fungi and protists are considered to be __________

Back 212

eukaryotic

Front 213

______________cells are surrounded by a cell membrane or plasma membrane

1)prokaryotes

2) eukaryotes

3)neither

4) both

Back 213

both

Front 214

where is DNA found in prokaryotic cells?

Back 214

in a nuclear region NOT surrounded by a membrane

Front 215

eukaryotic cells have a variety of ________ which are internal structures that are surrounded by one or more membrane

Back 215

organelles

Front 216

a unique characteristic of bacteria cell walls is the presence of _______________

Back 216

peptidoglycan

Front 217

is a prokaryote is considered to be a archaea, then it has ___________ cell walls

Back 217

pseudomurein

Front 218

"ancient" bacteria

Back 218

archaea

Front 219

____________are among the smallest organisms

Back 219

prokaryotes

Front 220

Prokaryotes reproduce via ________

Back 220

binary fission

Front 221

when the DNA is replicated, grows in size, pinched in the middle and then divides, this is considered to be ______________

Back 221

binary fission

Front 222

Eukaryotes reproduce via ___________

Back 222

mitosis

Front 223

when a cell divides into 2 daughter cells it is called __________

Back 223

mitiosis

Front 224

spherical bacteria are called ________

Back 224

coccus

Front 225

rodlike bacteria are called _________

Back 225

bacillus

Front 226

bacteria that are connected in chains are called

Back 226

strepto

Front 227

clusters of bacteria are _________

Back 227

staph

Front 228

the ___________ maintains the characteristic shape of the cell and prevents the cell from bursting with fluids flow into the cell

Back 228

cell wall

Front 229

murin

Back 229

another name for peptidoglycan is ___________

Front 230

the single most important component of the bacterial cell wall is the ________ that is similar to a chain link fence and can be multiple layers thick as seen in gram-positive cells

Back 230

peptidoglycan

Front 231

________ is found primarily on gram-negative bacteria, is a bilayer membrane that forms the outermost layer of the cell wall and is attached to the peptidoglycan by an almost continuous layer of small lipoprotein molecules

Back 231

outer membrane

Front 232

Glycocalyx

Back 232

a "sugar coat" found outside the bacterial cell

Front 233

endotoxin or LPS

Back 233

_________ is an important part of the outer membrane, is an integral part of the cell wall and is not released until the cell wall of bacteria is dead and breaking down. Used to identify gram-negative bacteria

Front 234

a distinguishing characteristic of many bacteria is the presence of a ______________ between the cell wall and the cell membrane

Back 234

periplasmic space

Front 235

a very active area of the metabolism in the bacteria that contains not only the cell wall peptidoglycan but also many digestive enzymes and transport proteins that destroy potentially harmful substances

Back 235

periplasmic space

Front 236

If peptidoglycan is digested from the cell wall of a gram-positive bacteria, they become _______ or cells with a cell membrane but no cell wall

Back 236

protoplasts

Front 237

In gram-negative, if the cell wall is digested away , they become ________ which have both a cell membrane and most of the outer membrane

Back 237

spheroplasts

Front 238

mycoplasma

Back 238

bacteria that belong to the genus _____________ have no cell wall but are protected by the the strengthened cell membrane that contains sterols

Front 239

bacteria that suddenly lose their ability to form cell walls are called __________, usually caused from either natural ocurance or from chemical treatment

Back 239

L-form

Front 240

the plasma membrane is also known as the ______

Back 240

cell membrane

Front 241

a living membrane that forms a boundry between the cell and its environment

Back 241

cell membrane

Front 242

the cell wall is made mostly of _______ and ________

Back 242

phospholipids , proteins

Front 243

the _______ of prokaryotic cells is the semifluid substance inside the cell membrane

Back 243

cytoplasm

Front 244

____________ consist of RNA and protein

Back 244

Ribosomes

Front 245

polyribosomes

Back 245

long chains of ribosomes

Front 246

neatly spherical, stain densly and contain a large and a small subunit

Back 246

Ribosomes

Front 247

__________ serve as a site for protein synthesis

Back 247

ribosomes

Front 248

instead of a nucleus, bacteria have what is called a __________ or ____________

Back 248

nuclear region, nucleiod

Front 249

the centrally located nuclear region of bacteria consists mostly of __________

Back 249

DNA

Front 250

photosynthetic bacteria and cyanobacteria contain internal membrane systems called ______________

Back 250

chromatophores

Front 251

bacteria can have within their cytoplasm a variety of small bodies collectively refered to as __________ that are sometimes called granules and cesicles

Back 251

inclusions

Front 252

granules

Back 252

the _______ is not bound by a membrane but it contains glycogen and polyphosphate, which are so densely compacted that they do not easily disolve in cytoplasm.

Front 253

glycogen

Back 253

a glucose polymer used for energy

Front 254

polyphosphate

Back 254

a phosphate polymer that supplies phosphate for a variety of metabolic processes.

Front 255

__________ are found outside the cell wall, attached to a protein hook, and anchored to the wall and membrane by the basal body

Back 255

flagella

Front 256

__________ is used to prevent phagocytosis, is neatly organized and made of sugar

Back 256

capsules

Front 257

when a flagella moves ____ it forms a bundle and pushes the bacteria in a "run" or forward motion

Back 257

counterclockwise

Front 258

when a flagella moves ___________ the bundle is disassembled, the flagella all come out and the bacteria tumbles randomly

Back 258

clockwise

Front 259

in a _____________ a bacteria will have an equal # of runs and tumbles

Back 259

buffer solution

Front 260

when a bacteria comes into contact with something they like, the flagella will cause it to ___________

Back 260

have longer runs and fewer tumbles

Front 261

a modification of a flagella found in spirochetes where the rotation causes the cell to move is called ______

Back 261

axial filaments

Front 262

another name for axial filaments

Back 262

endflagella

Front 263

_________ allows cell membranes to connect and exchange DNA

Back 263

"sex pili"

Front 264

_______ help bacteria adhere to the surface, such as the cell surface, water, and air, and contribute to the pathogenicity of certain bacteria.

Back 264

fimbriae and Pili

Front 265

a _______ is the protective structure outside the cell wall of the organism that secretes it. Only certain types of bacteria have this ability.

Back 265

capsule

Front 266

slime layer

Back 266

less tightly bound to the cell wall and is usually thinner than the capsule. this _________ protects the cell from drying out

Front 267

the ___________ is how the proteins move in and out in diferent directions depending on their function. Phospholopids rotate and move laterally and the membrane is a viscous as olive oil

Back 267

fluid mosaic model

Front 268

the prokaryotic __________ is constantly moving, shifting and very fluid, may be saturated or unsaturated and acts as a barrier that is very selective.

Back 268

plasma membrane

Front 269

osmosis

Back 269

the movement of water acorss a selectively permeable membrane from an area of high concentratino to low concentration

Front 270

osmotic pressure

Back 270

the pressure needed to stop the movement of water across the membrane

Front 271

active transport

Back 271

_____ involves energy in the form of ATP. When there is something going against the gradient, energy is used.

Front 272

movement of material across membranes happens via ________

Back 272

active transport

Front 273

__________ are environmentally and clinically important because they trigger the the expression of genes that form spores

Back 273

endospores

Front 274

in eukaryotic cells, the _______ contains the carbohydrates, attach to the proteins and steroids

ie: cholesterol

Back 274

plasma membrane

Front 275

in the eukaryotic cell, the _______ is full of matrix proteins that determine shape

Back 275

cytoplasm

Front 276

In eukaryotic cells, the ___ hold nucleuic acids

Back 276

nucleus

Front 277

In eukaryotic cells the __________ is the extensive system of membranes that form the tubes and plates of the cytoplasm, can be rough or smooth and contains the enzymes that sythesize lipids (especially those used to make the membrane)

Back 277

endoplasmic reticulum

Front 278

the _______of eukaryotic cells are larger than those found in prokaryotic cells, are ~60% RNA, and !40% protein. They provide sites for protein synthesis and some form chains that attach to the endoplasmic reticulum to make proteins for secretion from the cells.

Back 278

endoplasmic reticulum

Front 279

in eukaryotic cells, the _________ is a stack of flattened membranous sacs, that receives substances transported fromt he endoplasmic reticulum, stores the substances and alters their chemical structure. It also helps to form the plasma membrane and membranes of the lysosomes

Back 279

golgi apparatus

Front 280

in eukaryotic cells, you will find ________ which are extremely small membrane covered organells made by the golgi apperatus in animal cells. destroy invaders, digest and destroy.

Back 280

lysosomes

Front 281

in eukaryotic cells, you will find __________ which are small membrane enclosed organelles filled with enzymes. While they are found in both plants and animal cells, they have different functions. In animals they oxidize amino acids, and in plants the oxidize fats. They convert hydrogen peroxide to water in both plants and animals.

Back 281

peroxismomes

Front 282

In eukarytoic cells you will find ___________ which are membrane enclosed structures that store material such as starch, glycogen, or fat to be used for energy.

Back 282

vacuoles

Front 283

the __________ is a network of protein fibers make of microtubuals and microfiliments that supports and gives rigidity and shape to a cell. they have filiments that can be pulled in or away

Back 283

cytoskeleton

Front 284

is a structural polysaccharide that is also commonly found in the exoskeleton of arthropods, give regidity to cell walls to keep them from bursting as water moves in and out.

Back 284

chitin

Front 285

endosymbiotic theory

Back 285

at some point the eukariotic cells took in the prokaryotic cell where mutation occures. this was beneficial for both, though now they can not live without one another.

Front 286

________ moves a substance from the outside of a bacteria cell to the inside while chemically modifying the substance so it can not be defused out.

Back 286

group translocation reaction

Front 287

hypertonic

Back 287

a fluid is ________ if it causes the cells to shrivel or shrink as water moves out of them and into the fluid environment

Front 288

hypotonic

Back 288

the fluid is ________ to the cells if the cell swells or bursts as water moves from the environment into the cell.

Front 289

metabolism

Back 289

______is the sum of all the chemical processes carried out by a living organism

Front 290

anabolism

Back 290

the reactions that require energy to synthesize complex molecules from simplier ones is called ____________

Front 291

catabolism

Back 291

the reaction that releases energy by breaking complex molecules into smaller ones that can then be used as buuilding blocks.

Front 292

____________ is needed for growth, reproduction, and repair of cellular structures

Back 292

anabolism

Front 293

___________ is needed to provide organisms with energy for its life processes including movement, transport, and the synthesis of anabolism

Back 293

catabolism

Front 294

all catabolic reactions involve ______ which allows energy to be captured in high-energy bonds in ATP and similar molecules

Back 294

electron transfer

Front 295

___________ is directly related to oxidation and reduction

Back 295

electron transfer

Front 296

oxidation

Back 296

________can be defined as a loss or removal of electrons

Front 297

reduction

Back 297

can be defined as the gain of electrons

Front 298

autotrphy

Back 298

the self-feeding method of capturing energy to obtain carbon

Front 299

heterotrphy

Back 299

the other-feeding method of capturing energy to obtain carbon

Front 300

photoautotrophs

Back 300

obtain energy from light

Front 301

chemoautotrophs

Back 301

obtain energy from oxidizing simple inorganic substances such as sulfides and nitrites

Front 302

heterotrophs

Back 302

get their carbon from ready-made organic molecules which they obtain from other organisms living or dead

Front 303

photoheterotrophs

Back 303

obtain chemical energy from light

Front 304

chemoheterotrohs

Back 304

obtain chemical energy from breaking down ready-made organic compounds

Front 305

____________ metabolism is important as means of energy capture in many free-living organisms, such as microorganisms that do not cause diease

Back 305

autotrophic

Front 306

nearly all microorganisms, including nearly all those that cause infections are ___________

Back 306

chemoheterotrophs

Front 307

fermentation, glycolysis, and aerobic respiration are all methods used in _______

Back 307

chemoheterotrophs

Front 308

glycolysis and fermentation do not require _____ and only use a small amount of energy of the energy in glucose molecule is captured in the ATP

Back 308

oxygen

Front 309

_________ respiration requires oxygen as an electron acceptor and captures a reletively large amount of the energy in a glucose molecule in ATP

Back 309

aerobic

Front 310

all organic molecules are considered to be

Back 310

heterotrphs

Front 311

_______ pathways capture energy in a form cells can use

Back 311

catabolic

Front 312

__________ pathways make the complex molecules that form the structure of cells, enzymes, and other molecules that control cells

Back 312

anabolic

Front 313

bacteria transfers 40% of the energy in a glucose molecule to ATP during __________ metabolism. are organismsthat do not use oxygen; they include some that arekilled by exposure to oxygen

Back 313

aerobic

Front 314

energy released in a __________ reaction is captured, stored, in the form of ATP molecules which later get broken down to form energy needed to build up new molecules in biosynthetic pathways

Back 314

catabolic

Front 315

the energy required to start a reaction is called ______ and can be thought of a hurdle a molecule must be raised to get a reaction started

Back 315

activation energy

Front 316

each enzyme has a location on its surface called the _________ which is a binding site, that provides a surface on which reactions take place

Back 316

active site

Front 317

the substance in which an enzyme acts

Back 317

the substrate

Front 318

intracellular enzymes that act within the cell that produced them are _____

Back 318

endoenzymes

Front 319

extracellular enzymes that are synthesized on a cell but cross the cell membrane to act in the peroplasmic space or in the cell's immediate environment are _________

Back 319

exoenzymes

Front 320

many enzymes can catalize a reaction only if a substance called _______________ is present.

Back 320

coenzyme or cofactor

Front 321

a __________ is a nonprotein organi molecule bound to or loosely associated with an enzyme and are synthesized to form vitamins

Back 321

coenzyme

Front 322

a _________ is usually an inorganic ion such as magnesium, zinc, or mnganese, that improve the fit of an enzyme with its substrate and their presence can be essential in allowing a reaction to proceed

Back 322

cofactor

Front 323

A molecule similar in structure to a substrate cansometimes bind to an enzyme’sactive site even though the moleculeis unable to react. Thisnonsubstrate molecule is said toact as a_______ofthe reaction because it competeswith the substrate for the activesite

Back 323

competitive inhibitor

Front 324

the __________binds to an active site, itprevents the substrate frombinding and thereby inhibits thereaction.

Back 324

competitive inhibitor

Front 325

Enzymes also can be inhibited by substances called which distort the tertiary protein structure and alterthe shape of the active site. Any enzyme molecule thusaffected no longer can bind substrate, so it cannot catalyzea reaction.

Back 325

noncompetitive inhibitors

Front 326

Feedback inhibition

Back 326

________ is a kind of reversible noncompetitiveinhibition, regulates the rate of many metabolicpathways. For example, when an end product of apathway accumulates, the product often binds to and inactivatesthe enzyme that catalyzes the first reaction inthe pathway.

Front 327

Like other proteins,_____________ are affected by heat andby extremes of pH. Even small pH changes can alterthe electrical charge on various chemical groups thereby altering the abilityto bind its substrate and catalyze a reaction.

Back 327

enzymes

Front 328

Enzymes can catalyze a reaction to go in eitherdirection: AB ? A 1 B or A 1 B ? AB. The concentrationsof substrates and products are among severalfactors that determine the direction of a reaction. A highconcentration of_____drives the reaction toward formationof A and B.

Back 328

AB

Front 329

When neither AB nor A and B are removed fromthe system, the reaction will ultimately reach a steadystate known as _________ where nonet change in the concentrations of AB, A, or B occurs.

Back 329

chemical equilibrium

Front 330

The _________ of enzyme available usually controls therate of a metabolic reaction

Back 330

quantity

Front 331

The reaction rate __________ with the number ofenzyme molecules and reaches a maximum when allavailable enzyme molecules are working at full capacity.

Back 331

increases

Front 332

________is the metabolic pathway used bymost autotrophic and heterotrophic organisms, bothaerobes and anaerobes, to begin to break down glucose

Back 332

Glycolysis

Front 333

________ does not require oxygen, but it can occurin either the presence or absence of oxygen

Back 333

glycolysis

Front 334

_________is the additionof a phosphate group to a molecule, often from ATP.This addition generally increases the molecule’s energy.Thus, phosphate groups commonly serve as energy carriersin biochemical reactions.

Back 334

Phosphorylation

Front 335

After phosphorylation,__________ is broken into twothree-carbon molecules, and each molecule is oxidizedas two electrons are transferred from it to NAD.

Back 335

glucose

Front 336

Energy is captured in ATP at the ________ level, that is, in the direct course of glycolysis—in two separatereactions late in the process.

Back 336

substrate

Front 337

Because energyfrom two ATPs was used in the initial phosphorylations,glycolysis results in a net energy capture ofonly ____ ATPs per glucose molecule.

Back 337

two

Front 338

One process bywhich pyruvic acid is subsequentlymetabolized in the absenceof oxygen is_______

Back 338

fermentation

Front 339

_________ is the result of theneed to recycle the limitedamount of NAD by passing theelectrons of reduced NAD off toother molecules. It occurs bymany different pathways

Back 339

fermentation

Front 340

The simplest pathway for pyruvic acid metabolism is ___________in which only (homo-) lacticacid is made. Pyruvic acid is converteddirectly to lactic acid, using electrons from reducedNAD. Unlike other fermentations, this type produces nogas. It occurs in some types of the bacteria called lactobacilli,in streptococci, and in mammalian muscle cells.

Back 340

homolactic acid fermentation,

Front 341

In ________ carbon dioxideis released from pyruvic acid to form the intermediateacetaldehyde, which is quickly reduced to ethyl alcoholby electrons from reduced NAD., although rare in bacteria, is common in yeasts andis used in making bread and wine

Back 341

alcoholic fermentation

Front 342

Although aerobes obtain some of their energyfrom glycolysis, they use glycolysis chiefly as a preludeto a much more productive process, one that allowsthem to obtain far more of the energy potentially availablein glucose. This process is _________

Back 342

aerobic respiration

Front 343

the __________ metabolizes two-carbon units called acetyl groups to CO2 and H2O. It also is called the tricarboxylic acid(TCA) cycle, because some molecules in the cycle havethree carboxyl (COOH) groups, or the citric acid cycle,because citric acid is an important intermediate

Back 343

Krebs cycle

Front 344

Before pyruvic acid (the product of glycolysis) canenter the Krebs cycle, it must first be converted to __________ This complex reaction involves the removalof one molecule of CO2, transfer of electrons to NAD,and addition of coenzyme A

Back 344

acetyl-CoA.

Front 345

_______ is a sequence of reactions in whichacetyl groups are oxidized to carbon dioxide. Hydrogenatoms are also removed, and their electrons are transferredto coenzymes that serve as electron carriers. Each reaction is controlled by a specific enzyme, and themolecules are passed from one enzyme to the next as theygo through the cycle

Back 345

Krebs cycle

Front 346

___________ the process leading to the transferof electrons from substrate to O2, begins during oneof the energy-releasing dehydrogenation reactions ofcatabolism.

Back 346

Electron transport,

Front 347

the _________, which is often called the respiratory chain,

Back 347

electron transportchain

Front 348

ADP is converted to ATP by alarge ATP-synthesizing complex called ATP synthase(or ATPase) in a process known as_______.This process is the result of a seriesof chemical reactions that occur in and around a membrane.

Back 348

chemiosmosis

Front 349

___________performs two basicfunctions: (1) accepting electrons from an electron donorand transferring them to an electron acceptor, and(2) conserving for ATP synthesis some of the energy releasedduring the electron transfer.

Back 349

electron transport chain

Front 350

The large amountsof energy obtained from aerobic respiration result from the transfer of electrons through the electron transportchain, from a level of_________energy to one of_________ energy with the formation of ATP.

Back 350

high, low

Front 351

Energy is capturedin high-energy bonds as Pi combines with ADP toform ATP. This process is known as________________

Back 351

oxidative phosphorylation

Front 352

Inaerobic respiration,__________ is the final electron acceptorand becomes reduced to water

Back 352

oxygen

Front 353

From the metabolism of a single glucose molecule, ______pairs of electrons are transported by NAD

Back 353

10 (2 pairsfrom glycolysis, 2 pairs from the pyruvic acid to acetylCoAconversion, and 6 pairs from the Krebs cycle)

Front 354

Electrons entering at FADstart partway down the chain and contribute onlyenough energy to make two ATPs. Thus, during aerobicmetabolism of a glucose molecule, the 10 pairs of electronsfrom NAD produce 30 ATPs, and 2 pairs fromFAD produce 4 ATPs, for a total of 34 ATPs. Includingthe 2 ATP molecules from glycolysis and the 2 GTPmolecules (52 ATPs) from the Krebs cycle gives a totalyield of 38 ATPs per glucose molecule.

Front 355

Oxidative phosphorylation, when compared withfermentation, generates the _________amount of energyfrom glucose.

Back 355

greater

Front 356

The net gain of ATP molecules from fermentationis ______

Back 356

2

Front 357

Electrons for the hydrogen atoms removed from the reactionsof the Krebs cycle are transferred through theelectron transport system, which generates the highenergybonds of ATP. ADP is converted to ATP by alarge ATP-synthesizing complex called _________

Back 357

d ATP synthase(or ATPase)

Front 358

Chemiosmosis occurs in the __________ of prokaryotes

Back 358

cell membrane

Front 359

Chemiosmosis occurs in the __________ of eukaryotes

Back 359

mitochondrial membrane

Front 360

Some bacteria use only parts of the Krebs cycle and theelectron transport chain. They do notuse free O2 as their final electron acceptor.Instead, in aprocess called _________they use inorganicoxygen-containing molecules such as nitrate (NO23 ), nitrite(NO22 ), and sulfate (SO2 24 )

Back 360

anaerobic respiration

Front 361

Becauseanaerobes use less of the metabolic pathways, they produce _______ATP molecules than do aerobic organisms.

Back 361

fewer

Front 362

___________ breaks down the glucoseand pentose and produces NADPH (reduced) and nucleic acid precursors

Back 362

pentose phoshphate pathway

Front 363

____ produces NADPH (reduced) and ATP, does not involve glycoysis

Back 363

enter-Doudoroff pathway

Front 364

_______ re-oxidizes NADH (reduced) to allow NAD+ (oxidized) usage in glycolisis

Back 364

fermentation

Front 365

In the ____________ light strikesthe green pigment chlorophyll a in thylakoids of chloroplasts. Electrons in the chlorophyllbecome excited—that is, raised to a higher energy level.These electrons participate in generating ATP in cyclicphotophosphorylation and in noncyclic photoreduction

Back 365

light-dependent (light) reactions

Front 366

in _________excitedelectrons from chlorophyll are passed down an electrontransport chain. As they are transferred, energy is capturedin ATP by chemiosmosis . When theelectrons return to the chlorophyll, they can be excitedover and over again, so the process is said to be cyclic

Back 366

cyclic photophosphorylation

Front 367

In ___________ or carbonfixation, occur in the stroma of chloroplasts. Carbon dioxideis reduced by electrons from NADPH in a processknown as the Calvin-Benson cycle. Energy from ATP and electrons from NADPH arerequired in this synthetic process. Various carbohydrates,chiefly glucose, are the products of this reaction s

Back 367

light-independent (dark) reactions

Front 368

_______is typically a circular (in prokaryotes)or linear (in eukaryotes), threadlike molecule ofDNA

Back 368

chromosome

Front 369

Genes with different informationat the same locus are called __________

Back 369

alleles

Front 370

___________ is a permanent alterationin DNA. usually change the sequenceof nucleotides in DNA and thereby change theinformation in the DNA.

Back 370

mutations

Front 371

All the information for the structure and functioning ofa cell is stored in _______

Back 371

DNA

Front 372

DNA makes new DNA

Back 372

replication

Front 373

DNA makes RNA as the first stepin protein synthesis.In the overall process of protein synthesis, thesynthesis of mRNA from a DNA template is called_________

Back 373

transcription

Front 374

RNA links amino acids together toform proteins. The synthesis of protein from informationin mRNA is called

Back 374

translation

Front 375

In protein synthesis, the new polymer is a particular typeof RNA called __________ which thenserves as a second template that dictates the arrangementof amino acids in a protein. Some proteins form the structureof a cell, others (enzymes) regulate its metabolism,and still others transport substances across a membrane

Back 375

mRNA

Front 376

In ___________ aprocess whereby RNA can make DNA. This DNA canthen make more RNA. Such viruses are known as retrovirusesbecause of this reverse process.

Back 376

reverse transcription

Front 377

________is a less accurate process than regular transcription. Uncorrectederrors are passed on as mutations, or permanentchanges in the genes of an organism.

Back 377

reverse transcription

Front 378

_________ the points at which the two strands of DNAseparate to allow replication of DNA

Back 378

replicationforks

Front 379

Molecules of the enzyme _________ movealong behind each replication fork, synthesizing newDNA strands complementary to the original ones at aspeed of approximately 1,000 nucleotides per second and also growing strand,correcting errors such as mismatched bases.

Back 379

DNA polymerase

Front 380

The enzyme DNA polymerase can add nucleotidesonly to the _____end of a growing DNA strand.

Back 380

3"

Front 381

s atemplate for the synthesis of a continuous new strand that going in the 50 to 30 direction.

Back 381

leading strand

Front 382

runs in the 30 to 50 direction, thesynthesis of new DNA, the ______________ must be discontinuous;that is, the polymerase must continuallyjump ahead and work backward, making a series ofshort DNA segments called Okazaki fragments.

Back 382

lagging strand

Front 383

DNA polymerase will digest the RNAprimer and replace it with DNA. The fragments are thenjoined together by another enzyme called a _______

Back 383

ligase

Front 384

After separatingthe DNA strands, the enzyme __________binds toone strand of exposed DNA recognizing a sequence ofnucleotide bases in the DNA that indicates this is the startof a gene (promoter sequence)

Back 384

RNA polymerase

Front 385

In prokaryotes, transcription and translation bothtake place in the _________

Back 385

cytoplasm

Front 386

in eukaryotes, transcriptiontakes place in the __________

Back 386

cell nucleus

Front 387

___________binds closely to certainproteins to form two kinds of ribosome subunits. A subunitof each kind combines to form a ribosome. They serve as binding sites fortransfer RNA, and some of their proteins act as enzymesthat control protein synthesis

Back 387

Ribosomal RNA (rRNA)

Front 388

_______ is synthesized in unitsthat contain sufficient information to direct the synthesisof one or more polypeptide chains.

Back 388

Messenger RNA (mRNA)

Front 389

The first codon in a molecule of mRNA acts as a ________and always codes for the amino acid methionine,even though the methionine may be removed fromthe protein later

Back 389

start codon

Front 390

The last codon to be translated in amolecule of mRNA is a ___________ and acts as a kind of punctuation mark to indicate the end ofa protein molecule

Back 390

terminator (stop codon)

Front 391

codons thatcode for an amino acid are called______

Back 391

sense codons

Front 392

Although geneticinformation is stored in DNA, the genetic code is writtenin codons of _____

Back 392

mRNA

Front 393

The function of _________ is to transfer amino acids fromthe cytoplasm to the ribosomes for placementin a protein molecule

Back 393

transfer RNA(tRNA)

Front 394

Each tRNA has athree-base __________ that is complementaryto a particular mRNA codon. It also has a bindingsite for an amino acid—the particular amino acidspecified by the mRNA codon

Back 394

anticodon

Front 395

Found in the cytoplasm, where they pick upamino acids and transfer them to mRNA

Back 395

transfer RNA

Front 396

___________ is an important process in bacterial growth,uses 80 to 90% of a bacterial cell’s energy.

Back 396

Protein synthesis,

Front 397

Thelocation on the ribosome where the first tRNA pairs iscalled the ______

Back 397

P site

Front 398

The second codon of the mRNA thenpairs with a tRNA that transports the second amino acidto the ____

Back 398

A site

Front 399

__________shuttle back and forthpicking up amino acids in the cytoplasm, and bringing themto the ribosome, where the amino acids are incorporatedinto protein.

Back 399

tRNAs

Front 400

In __________ enzyme activity is regulateddirectly, and the control mechanism determines how rapidlyenzymes already present will catalyze reactions.

Back 400

feedback inhibition

Front 401

In _____________ regulation occursindirectly by enzyme synthesis, and the control mechanismdetermines which enzymes will be synthesized andin what amounts.

Back 401

enzyme induction and enzyme repression

Front 402

In feedback inhibition, also called________the end product of a biosynthetic pathway directlyinhibits the first enzyme in the pathway.

Back 402

end-product inhibition

Front 403

At one point in the investigation of metabolic regulation,it was discovered that certain organisms alwayscontain active enzymes for glucose metabolism evenwhen glucose is not present in the medium. Such enzymesare called ___________

Back 403

constitutive enzymes

Front 404

When lactose is present,however, the cells synthesize the enzymes needed forits metabolism. This phenomenon is __________ controls the breakdownof nutrients as they become available in the growthmedium. Such a system is turned on when a nutrient isavailable and turned off when it is depleted

Back 404

enzyme induction

Front 405

______, a model that explainsthe regulation of some protein synthesis in bacteria

Back 405

operon (op0er-on) theory,

Front 406

_______ is a sequenceof closely associated genes that regulate enzyme production.

Back 406

operon

Front 407

An operon includes one or more ___________ which carry information for the synthesis of specific proteinssuch as enzyme molecules

Back 407

structural genes

Front 408

__________ control the expression of the structural genes.

Back 408

regulatory site

Front 409

___works in conjunction with the operonbut may be located some distance from it

Back 409

regulator (i) gene

Front 410

_____ is a protein that binds to theoperator and prevents transcription of the adjacent Z, Y,and A genes. Consequently, the enzymes that metabolizelactose are not synthesized.

Back 410

repressor

Front 411

When present in the medium, lactose acts as the _________ by binding to and inactivating the lac repressor.TheRNA polymerase then binds to the promoter, causingthe operator to initiate transcription of the Z, Y, and Agenes as a single long strand of mRNA.

Back 411

inducer

Front 412

_______ breaks downlactose into glucose and galactose

Back 412

b-galactosidase

Front 413

______typically regulatesanabolism. It controls processes in which substancesneeded for growth are synthesized. Synthesis of theamino acid tryptophan, for example

Back 413

enzyme repression

Front 414

_________ allows transcriptionof the trp operon to begin but terminates it prematurelyby a complex process when sufficient amounts oftryptophan are already present in the cell.

Back 414

attenuation,

Front 415

the lac operon that we describedpreviously is repressed when glucose is presentin adequate quantities, an effect known as _________ In this way the cell saves energy by not makingenzymes it doesn’t need

Back 415

catabolite repression

Front 416

__________ refers to the genetic informationcontained in the DNA of the organism

Back 416

Genotype

Front 417

_______refers to the specific characteristics displayed by the organism.

Back 417

Phenotype

Front 418

Mutations always change the_______

Back 418

genotype.

Front 419

________ is a mutation that affect a single base. is a base substitution, or nucleotidereplacement, in which one base is substituted foranother at a specific location in a gene. The mutationchanges a single codon in mRNA, and it may or may notchange the amino acid sequence in a protein.

Back 419

point mutations,

Front 420

__________is a mutation that can affect more than one base in DNA. n is a mutation in which there isa deletion or an insertion of one or more bases. Such mutations alter all the three-base sequencesbeyond the deletion or insertion. When mRNA transcribedfrom such altered DNA is used to synthesize aprotein, many amino acids in the sequence may be altered.

Back 420

frameshift mutations

Front 421

bacteria that have lost the ability to synthesizea particular enzyme have played an importantrole in our understanding of metabolic pathways. Suchnutritionally deficient mutants are called _______they require special substances in their medium to maintaingrowth.

Back 421

auxotrophs

Front 422

normal, nonmutantforms are called _______ orwild types.

Back 422

prototrophs

Front 423

__________ occurin the absence of any agent known tocause changes in DNA. They ariseduring the replication of DNA and appearto be due to errors in the basepairing of nucleotides in the old andnew strands of DNA.

Back 423

Spontaneous mutations

Front 424

________ are produced by agents called mutagens,which increase the mutation rate above the spontaneousmutation rate. Mutagens include chemical agentsand radiation

Back 424

Induced mutations

Front 425

_________ is a is a molecule quite similar in structureto one of the nitrogenous bases normally found in DNA.

Back 425

base analog

Front 426

__________ are are substances that add alkylgroups (such as a methyl group, —CH3) to other molecules. Such a change can give rise to a point mutation.

Back 426

Alkylating agents

Front 427

_____________ such as nitrous acid (HNO2)remove an amino group (—NH2) from a nitrogenous base. Removing an amino group from adenine causes itto resemble guanine

Back 427

Deaminating agents

Front 428

__________ cause frameshift mutations.. This moleculeor one of its derivatives can become inserted in the DNAdouble helix, displacing both members of a base pair.Such a modification distorts the helix and causes partialunwinding of the DNA strands.

Back 428

, acridine derivatives

Front 429

_________occurs in the presenceof visible light in bacteria previously exposed toultraviolet light. When organisms containing dimers arekept in visible light, the light activates an enzyme thatbreaks the bonds between the pyrimidines of a dimer

Back 429

photoreactivation

Front 430

________ occurs in some bacteria, and cantake place in the presence or absence of light, requiresseveral enzyme-controlled reactions

Back 430

Dark repair