Bact Exam 3

Front 1

book: organic matter in macromolecules formed by these bonds

Back 1

anhydride bonds

Front 2

book: energy used to synthesize anhydride bonds comes from these sources

Back 2

ATP and proton motive force

Front 3

book: three major mechanisms for generating metabolic energy

Back 3

fermentation, respiration, and photosynthesis

Front 4

book: fermentation is characterized by this enzymatic process in which a pyrophosphate bond is donated directly to ADP by a phosphorylated metabolic intermediate

Back 4

substrate phosphorylation

Front 5

creatures that do not require organic nutrients for growth

Back 5

autotrophs

Front 6

organisms that use an inorganic substrate such as hydrogen or thiosulfate as a reductant and carbon dioxide as a carbon source

Back 6

chemolithotrophs

Front 7

require organic carbon for growth

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heterotrophs

Front 8

the ability to assimilate N2 reductively via NH3 is called

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nitrogen fixation

Front 9

production of NH3 from deamination of amino acids is called

Back 9

ammonification

Front 10

ability to assimilate nitrate reductively by conversion of ion to NH3

Back 10

assimilatory nitrate reduction

Front 11

ability to assimilate nitrite reductively by conversion of ion to NH3

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assimilatory nitrite reduction

Front 12

pathways used by organisms that employ ions as terminal electron acceptors in respiration

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dissimilation

Front 13

converting NH3 to gaseous N2 under anaerobic conditions is called

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denitrification

Front 14

reaction of ammonia oxidized by nitrite, occurs in anoxic waters of ocean and a major pathway by which nitrogen is returned to atmoshere

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anammox

Front 15

compounds that chelate iron and promote its transport as a soluble complex

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siderophores

Front 16

organic compound that a cell must contain in order to grow but cannot synthesize

Back 16

growth factor

Front 17

acetate to lipids has two intermediates

Back 17

isoprenoid precursors and fatty acids (separate pathways)

Front 18

organisms that grow at well above temperature of boiling

Back 18

hyperthermophilic

Front 19

enzyme that protects aerobes and aerotolerant anaerobes from hydrogen peroxide and superoxide

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superoxide dismutase (breaks down superoxide O2) and catalase (breaks down h2o2)

Front 20

h202 very toxic to cells why?

Back 20

kills DNA, especially recA that deals with fixing damage

Front 21

organisms requiring high salt concentrations

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halophilic

Front 22

organisms requiring high osmotic pressures

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osmophilic

Front 23

a medium that will cause the colonies of a particular type of organism to have a distinctive appearance

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differential medium

Front 24

procedure whereby medium is prepared so as to duplicate natural environment of desired microorganism, thereby selecting for it

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enrichment culture

Front 25

acidic polysaccharide extracted from certain red algae that is used to plate organisms for minimal movement

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agar

Front 26

polymerization of building blocks (amino acids) into macromolecules (proteins) is achieved largely through this reaction

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dehydration

Front 27

optimal temp curve

Back 27

on a graph where you have the greatest distance between inactivation vs temp and growth vs temp

Front 28

optimum temp of 5 degrees C

Back 28

psychrophiles - gram positive spore forming anaerobe, causes food (botulism)

Front 29

what allows psychrophiles to withstand cold

Back 29

more CG in DNA, cell membrane has more lipids

Front 30

optimal temp of 10-50 deegrees C

Back 30

mesophiles
on skin have temp of 32 C

Front 31

optimum temp is 45 C

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thermophiles

Front 32

can survive high temps but prefer lower ones

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thermoduric

Front 33

heat shock response

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increasing temp causes sigma factor to tell genes to make heat shock genes that make heat shock proteins

Front 34

3 instances of sigma factors

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sporulation, stationary phase, heat shock

Front 35

HSP 70 role

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prevents aggregation of newly synthesized proteins in presence of higher temp
stabilizes unfolded proteins and helps them get into proper confirmation to start folding

Front 36

HSP 10 and HSP 60

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molecular chaperones that catalyze correct folding of misfolded proteins

Front 37

remove denatured proteins in heat shock

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proteases

Front 38

one way to get rid of organisms, such as spores, that would otherwise be a problem

Back 38

heat them up

Front 39

protects bacteria by shielding

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clumping

Front 40

this material protects against heat damage

Back 40

lipids

Front 41

put a drop of lipid/protein in a cell, what forms and protects from heat damage

Back 41

micelle

Front 42

how does viscosity play a role in heat protection

Back 42

more viscous, more protection

Front 43

how does depth affect heat protection

Back 43

cells deeper, and thus farther away from the heat, are more protected

Front 44

does altering the pH affect the temperature at which something is denatured?

Back 44

yes, if you take the enzyme out of its optimal pH, and then add heat, it takes less time than just adding heat to denature

Front 45

this freezing results in death of bacteria

Back 45

slow freezing

Front 46

why does slow freezing kill bacteria

Back 46

as it freezes, amount of water decreases, which increases osmotic pressure eventually bursting the cell
also the concentration of toxic products increase
ice crystals become swords

Front 47

technique used in lab to break open cell to see enzymes inside

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freeze/thaw technique

Front 48

type of freezing that results in preservation

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rapid freezing

Front 49

when you rapid freeze something, what form does it end up in

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amorphous solid (no crystals)

Front 50

final step of rapid freezing?

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remove water with vacuum (sublimation - turns solid to a gas)

Front 51

freeze dry technique AKA

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lyophilization

Front 52

explain freeze/dry technique

Back 52

dip small piece of paper into culture, place in vial, evacuate air, freeze with liquid nitrogen and seal.

Front 53

require oxygen at high concentration (10-20%)

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aerobes

Front 54

require oxygen at low concentration (2-10%)

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microaerophiles

Front 55

can live with or without oxygen

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facultative anaerobes

Front 56

can grow only without oxygen

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obligate anaerobes

Front 57

why is oxygen toxic to obligate anaerobes

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during process of flavoprotein oxidation, superoxide radicals are produced. these damage DNA, protein, and the cell membrane, killing the cell.

Front 58

breaks down superoxide radical

Back 58

superoxide dismutase

Front 59

breaks down hydrogen peroxide

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catalase

Front 60

do aerobes have catalase and superoxide dismutase

Back 60

yes, both

Front 61

do microaerophiles have catalase and superoxide dismutase?

Back 61

do not have catalase, but do have peroxidase (not as efficient). if only a little hydrogen peroxide, not a problem. Too much hydrogen peroxide will kill the cell

Front 62

do obligate anaerobes have catalase and superoxide dismutase?

Back 62

no, and if you grow them in air, superoxide radicals are made killing the cell

Front 63

if you oxidize this group with protein oxygen, you may lose protein structure and enzyme activity, proving oxygen is toxic

Back 63

sulfhydryl (SH)

Front 64

oxygen could be toxic because it oxidizes this compound

Back 64

NADH

Front 65

two types of obligate anaerobes

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spore forming and nonspore forming

Front 66

this obligate anaerobe produces a *neurotoxin*, and infects host, showing signs of paralysis because muscles all contract

Back 66

tetanus- is spore forming, can live on rusty nail for long time

Front 67

this obligate anaerobe produces a *neurotoxin* causing all muscles to be flaccid

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clostridium botulism

Front 68

this obligate anaerobe causes gas gangrene from soil organisms on metal

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perfringens

Front 69

three spore forming obligate anaerobes

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tetanus, botulism and perfringens

Front 70

obligate anaerobe in the gut, most numerous

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bacteroidas - didnt know this because it died when exposed to air and couldnt be studied

Front 71

obligate anaerobe in the mouth

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fusiform

Front 72

how to transport anaerobes

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anaerobic culturette - soft plastic tube with cover
in lab, thioglycollate broth keeps oxygen out

Front 73

how to grow anaerobes in a solid media

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gas pack - water in here removes oxygen from the chamber

Front 74

acidophiles

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pH 6.5 - 7

Front 75

neutrophiles

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pH 7-8

Front 76

Alkalophiles

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8.4-9

Front 77

pH of human pathogens

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7.2-7.6

Front 78

pH of fungi

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4-6

Front 79

tolerated range of pH units

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3-4 units

Front 80

area of rapid growth with pH

Back 80

within 1 pH unit

Front 81

produces acetic acid, cells pump out acid, pH becomes very low and still grows

Back 81

acetobactor

Front 82

this is happy at pH nine, and how is this helpful

Back 82

vibrio cholerae
has diagnostic significance, can help us narrow the identification as being able to grow in high pH

Front 83

cell is more permeable to (undissociated or dissociated) form

Back 83

more permeable to undissociated form

Front 84

why is the undissociated form bad for enzyme activity

Back 84

this reflects low pH which inhibits enzyme activity

Front 85

how do cells maintain their own pH

Back 85

transport protons in and out
convert acidic to neutral molecules
synthesize polyamines with ornithine decarboxylase
lysine decarboxylase does the same thing

Front 86

ornithine decarboxylase gives this end product

lysine decarboxylase gives this end product

Back 86

putrescine

cadaverine

Front 87

cells that survive transport through acidic stomach

Back 87

amino acid decarboxylases - keep internal pH normal

Front 88

how to keep medium at a set pH

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buffered medium
or
organic molecules such as peptones and amino acids to keep pH constant by soaking up protons

Front 89

osmolarity refers to

Back 89

salt concentration

Front 90

low salt in external medium, high water

Back 90

hypotonic

Front 91

high salt in external medium, low water

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hypertonic

Front 92

salt lovers in marine environments

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halophiles

Front 93

how does cell survive in hypotonic solution

Back 93

cell wall keeps the pressure in

Front 94

osmotically fragile

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protoplasts and spheroplasts (lost cell wall)
mycoplasma - never had cell wall

Front 95

how does cell maintain internal osmolarity in cytoplasm

Back 95

increase/decrease K+ to control salt concentrations
increase/decrease synthesis of polyamines
control synthesis/uptake of osmoprotectants (proline and betaine - stabilize proteins in presence of high salt)

Front 96

what does MDO stand for

Back 96

membrane derived oligosaccharides

Front 97

if salt in medium is high, what is mdo

Back 97

MDO low

Front 98

which wavelength has highest energy

Back 98

short

Front 99

UV light causes this problem in DNA

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pyrimidine dimer formation

Front 100

X-rays cause this problem in DNA

Back 100

single strand breaks

Front 101

alkylation causes this problem in DNA

Back 101

alteration of bases

Front 102

some drugs, such as mytomycin C, can damage DNA by joining, known as;

Back 102

cross linkage

Front 103

brief inhibition of DNA synthesis causes:

Back 103

gaps in DNA

Front 104

this form of direct repair uses photolyases to remove thymine dimers

Back 104

photoreactivation

Front 105

in the adaptive response in fixing methylated bases, the methyl group is transferred to what amino acid?

Back 105

cysteine

Front 106

this enzyme removes methyl purines or methyl pyrimidines, not just the methyl group

Back 106

DNA glycosylase II

Front 107

when RecA scans the DNA and finds an error, what is its response?

Back 107

binds, becomes protease and cleaves lex A repressor allowing DNA repair enzymes to be made

Front 108

organisms that can survive high ATMs but whrive at 1 ATM

Back 108

barotolerant

Front 109

organisms that grow best at 400 ATM

Back 109

moderate barophiles

Front 110

organisms that will grow at high pressure only

Back 110

extreme barophiles

Front 111

process where sound waves induce formation of air bubbles that lead to lysis

Back 111

cavitation