Microbial metabolism Flashcards

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1
Q

what is metabolism

A

chemical reactions inside the cell

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2
Q

what are exergonic reactions

A

reactions that are spontaneous and release energy

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3
Q

what are endergonic reactions

A

reactions that require energy

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4
Q

what is anabolism

A

endergonic metabolic pathways involved in biosynthesis, converting simple molecular building blocks into more complex molecules, fuels by the use of cellular energy

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5
Q

what is catabolism

A

exergonic pathways that break down complex molecules into simpler ones

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6
Q

what pathway releases energy stored in complex molecules

A

catabolic pathways

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7
Q

what are autotrophs

A

organisms that convert inorganic carbon dioxide into organic carbon compounds

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8
Q

what are examples of autotrophs

A

plants and cyanobacteria

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9
Q

what are heterotrophs

A

organisms that rely on organic compounds such as nutrients from autotrophs

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10
Q

what is energy derived from

A

the transfer of electrons

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11
Q

what are phototrophs

A

organisms that get their energy from light

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12
Q

what are chemotrophs

A

organisms that obtain energy for electron transfer by breaking chemical bonds

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13
Q

what are orgnotrophs

A

chemothrophs that get energy from organic compounds

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14
Q

what are lithotrophs

A

chemotrophs that get energy from inorganic compounds, including hydrogen sulfide and reduced iron

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15
Q

example of inorganic carbon chemoautotrophs

A

hydrogen
sulfur
iron
nitrogen
carbon monoxide oxidizing bacteria

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16
Q

chemoheterotrophs examples

A

all animals, most fungi, protozoa, and bacteria

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17
Q

photoautotroph examples

A

all plants, algae, cyanobacteria, green and purple sulfur bacteria

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18
Q

Photoheterotrophs examples

A

Greenland purple non sulfur bacteria, heliobacteria

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19
Q

What are oxidation reaction

A

reactions that remove electrons from donor molecules, leaving them oxidized

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20
Q

what are reduction reactions

A

reactions that add electrons to acceptor molecules leaving them reduced

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21
Q

what is a redox reaction

A

oxidation and reduction reactions happening in tandem

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22
Q

how is the energy released from the breakdown of chemical bonds within nutrients stored

A

either electron carriers or in ATP

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23
Q

what are electron carriers

A

molecules that bind to and shuttle high-energy electrons between compounds in pathways

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24
Q

where do the principle electrons carrier come from

A

the B vitamin group

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25
Q

what is the most common mobile electron carrier

A

NAD+/NADH

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26
Q

what is NAD+

A

the oxidized from of nicotinamide adenine dinucleotide

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27
Q

what is NADH

A

the reduced form of NAD+

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28
Q

what is NADP+

A

nicotine adenine dinucleotide phosphate the oxidized from of an NAD+ that contains an extra phosphate group

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29
Q

what is NADP+ when reduced

A

NADPH

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30
Q

what is FAD

A

the oxidized form of flavin adenine dinucleotide

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31
Q

what is the reduced form of FAD

A

FADH2

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32
Q

what are NAD+/ NADH and FAD/FADH2 used in

A

energy extraction from sugars during catabolism in chemoheterotrophs

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33
Q

what are NADP+/NADPH used for

A

anabolic reactions and photosynthesis

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34
Q

what are FADH2, NADH and NADPH referred to

A

as having reducing power due to their ability to donate electrons to various chemical reactions

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35
Q

What molecule is at the heart of ATP

A

AMP- adenosine monophosphate

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36
Q

what is AMP composed of

A

an adenine molecule bonded to a ribose molecule and a single phosphate group

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37
Q

what is ribose

A

a five carbon sugar found in RNA

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38
Q

what is AMP a nucleotide of

A

RNA

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39
Q

what does a second phosphate group added to MAP form

A

ADP-adenosine diphosphate

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40
Q

what does the addition of a 3rd phosphate group added to MAP result in

A

ATP

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41
Q

why is phosphorylation

A

adding a phosphate group to a molecule

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42
Q

how do phosphate groups act in series

A

they are negatively charged and repel each other

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43
Q

what does phosphate repelling each other do to ADP and ATP

A

it makes them inherently unstable

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44
Q

what are the bonds in ADP and ATP called

A

high-energy phosphate bonds

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45
Q

what happens when high-energy bonds are broken to release phosphate

A

dephosphprylation, energy is released to drive endergonic reactions

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46
Q

what is a catalyst

A

a substance that helps speed up a chemical reactions

47
Q

why are catalysts reusable

A

they are to used or changed during chemical reactions

48
Q

what are enzymes

A

proteins that serve as catalysts for biochemical reactions inside cells

49
Q

how do enzymes function

A

by lowering the activation energy of a chemical reaction in the cell

50
Q

what is activation energy

A

energy needed to form or break a chemical bond and convert reactants to products

51
Q

how do enzymes lower activation energy

A

by binding to the reactant molecules and holding them in such a way as to speed up the reaction

52
Q

what are substrates

A

the chemical reactants to which an enzyme binds

53
Q

what is an active site

A

the location within the enzyme where the substrate binds

54
Q

what is the match between an enzyme and substrate like

A

a jigsaw puzzle

55
Q

what happens when an enzyme binds to its substrate

A

the enzyme structure changes slightly to find the best fit between the transition state and the active site

56
Q

what is induced fit

A

active-site modification in the presence of substrate with simultaneous formation of the transition state

57
Q

what conditions influence enzymes

A

PH
substrate concentration
temperature

58
Q

what happens to enzymes when environmental temperature is increased

A

reaction rate increases, they eventually denature and lose 3d structure and function

59
Q

what happens to enzymes outside the suitable temperature range

A

chemical bonds in the active site are affected making them less well suited to bind substrates

60
Q

what happens to enzymes at higher concentrations of substrates

A

activities increase at higher concentrations until ir reaches saturation and no longer bind

61
Q

at what temperature to human pathogen enzymes work best

A

37C

62
Q

what are the two helper molecules

A

cofactors and coenzymes

63
Q

what are cofactors

A

inorganic ions such as iron and magnesium that help stabilize enzyme conformation and function

64
Q

what enzyme requires bound zinc ion to function

A

DNA polymerase

65
Q

what are coenzymes

A

organic helper molecules that are required for enzyme action

66
Q

what are the most common sources of coenzyme

A

dietary vitamins

67
Q

are coenzymes reusable

A

yes

68
Q

what does coenzyme a do

A

binds to the enzymes active site aiding in the transition of a substrate to a product

69
Q

what is an apoenzyme

A

an enzyme lacking a necessary cofactor or coenzyme and is inactive

70
Q

what is a holoenzyme

A

an Enzyme with the necessary associated cofactor or coenzyme and is active

71
Q

what are other coenzymes that provide high-energy electrons or phosphate groups to bind enzymes

A

NADH and ATP

72
Q

what is a competitive inhibitor

A

a molecule similar enough to a substrate that it can compete with the substrate and bind to an active site by blocking the substrate from binding

73
Q

what is required for a competitive inhibitor be effective

A

the inhibitor concentration needs to be approximately equal to the substrate concentration

74
Q

how do sulfa drugs work

A

they bind to the active site of an enzyme within bacterial folic acid synthesis pathway prevention folic acid synthesis and bacterial growth

75
Q

what does a noncompetitive inhibitor do

A

binds to the enzyme at an allosteric site to block substrate binding to the active site

76
Q

how does a noncompetitive inhibitor block substrate

A

by inducing conformational change that reduces the affinity of the enzyme for its substrate

77
Q

what concentration is needed for noncompetitive inhibitors

A

lower than substrate concentration

78
Q

what does an allosteric activator do

A

binds to an enzyme away from the active site inducing conformational change, increasing the affinity of the enzymes active site for its substrate

79
Q

what is feedback inhibition

A

the use of a pathway product to regulate its own further production

80
Q

What is glycolysis

A

the most common pathway for the catabolism of glucose for bacteria, eukaryotes and archaea

81
Q

What does glycolysis do

A

produces energy, reduced electron carriers and precursor molecules for cellular metabolism

82
Q

does glycolysis use oxygen

A

no

83
Q

where does glycolysis take place

A

the cytoplasm of cell

84
Q

what does glycolysis begin with

A

6-carbon glucose molecule

85
Q

what does glycolysis end with

A

two molecules of a three carbon sugar called pyrubate

86
Q

what does glycolysis using the emp pathway consist of

A

energy investment phase
energy payoff phase

87
Q

what happens in the energy investment phase of the EMP pathway

A

energy from two atp molecules modify a glucose so the 6 carbon sugar can be split evenly into two phosphorylated three carbon molecules called glyceraldehyde 3 phosphate

88
Q

what happens during the energy payoff phase of EMP

A

energy is extracted by oxidizing G3P to pyruvate producing four ATP moleculsing and reducing 2 molecules of NAD+ to two molecules of NADH using electrons from original glucose

89
Q

what do the ATP molecules produced during the energy payoff phase of glycolysis formed by

A

substrate-level phosphorylation

90
Q

what happens during substrate level phosphorylation

A

a phosphate group is removed group is removed from an organic molecule and is directly transferred to an available ADP molecule producing ATP

91
Q

what is the net gain from a single glucose molecule during glycolysis

A

2 ATP
2 NADH
2 pyruvate

92
Q

what is the main glycolysis pathway

A

EMP pathway, used by animals and many bacteria

93
Q

what is the alternate glycolytic pathway used by many prokaryotes

A

ED pathway

94
Q

what is the 3rd type of glycolytic pathway that occurs in all cells

A

PPP

95
Q

what is considered the most ancient universal glycolytic pathway

A

PPP

96
Q

what are the intermediates from the PPP used for

A

biosynthesis of nucleotides and amino acids

97
Q

when will the PPP pathway be preferred

A

when nucleic acid or protein synthesis is needed

98
Q

what must happen for pyruvate to be further oxidized

A

it must first be decarboxylated

99
Q

what enzyme is required o decarboxylate (transition reaction) pyruvate

A

pyruvate dehydrogenase

100
Q

describe pyruvate dehydrogenase

A

a two carbon acetyl group

101
Q

what must pyruvate dehydrogenase attach to

A

coenzyme a

102
Q

where doe the transition reaction occur

A

the mitochondrial matrix of eukaryotes and cytoplasm of prokaryotes

103
Q

what does the Krebs cycle do

A

transfers remaining electrons from the acetyl group produced during the transition reaction to electron carrier molecules reducing them

104
Q

where does the Krebs cycle take place in prokaryotes

A

cytoplasm

105
Q

what makes the Krebs cycle different from glycolysis

A

it is a closed loop,

106
Q

what happens in the last step of the Krebs cycle

A

the compound using in the first step is regenerated

107
Q

what does the kern cycle do

A

a series of chemical reactions that capture the 2 carbon acetyl group and adds them to a four carbon intermediate producing a 6 carbon intermediate citric acid

108
Q

What does the Kreb cycle produce

A

2 CO2
1 ATP
3NADH
1 FADH2

109
Q

what can be produced using the Krebs cycle

A

glucose metabolism
amino acids
chlorophylls
fatty acids
nucleotides

110
Q

is the Krebs cycle anabolic or catabolic

A

both

111
Q

when does oxidative phosphorylation occur

A

during cellular respiration

112
Q

how is most ATP generated

A

oxidative phosphorylation

113
Q
A