Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochem > Chapter 14 > Flashcards

Chapter 14 Flashcards

1
Q

the free energy released from catabolic oxidation reactions is used to driver …

A

endergonic anabolic rxns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

nutrition is the intake and utilization of food to supply … and …

A

free energy; raw materials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

heterotrophic organisms obtain their free energy from compounds synthesized by … or … organisms

A

chemolithotrophic; photoautotrophic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

food contains …, …, …, …, …, and …

A

proteins; carbohydrates; fats; water; vitamins; minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

metabolic pathways are sequences of enzyme-catalyzed reactions that occur in

A

different cellular locations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

near-equilibrium reactions are …, whereas reactions that function far from equilibrium serve as … points and render metabolic pathways …

A

freely reversible; regulatory; irreversible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

flux through a metabolic pathway is controlled by regulating the activities of the enzymes that catalyze its

A

rate-determining steps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

the free energy of the “high-energy” compound ATP is made available through cleavage of one or both of its ….

A

phosphoanhydride bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

an exergonic rxn such as ATP or PPi hydrolysis can be coupled to an … rxn to make it more favorable

A

endergonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

substrate-level phosphorylation is the synthesis of ATP from … by … from another compound

A

ADP; phosphoryl group transfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

the common product of carbohydrate, lipid, and protein catabolism, …, is a “high-energy” …

A

acetyl-CoA; thioester

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

the coenzymes … and … are reversibly reduced during the oxidation of metabolites

A

NAD+; FAD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

the Nernst equation relates the electromotive force of a redox rxn to the … and concentrations of the … and …

A

standard reduction potentials; electron donors; acceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

electrons flow spontaneously from the reduced member of a redox couple with the … to the oxidized member of a redox couple with the …

A

lower reduction potential; higher reduction potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

studies of metabolic pathways determine the order of metabolic transformations, their …, their …, and their … to metabolic processes in other tissues

A

enzymatic mechanisms; regulation; relationships

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

metabolic pathways are studied using … and … tracers, …, natural and engineered …, …, and … techniques

A

isotopic; fluorescent; enzyme inhibitors; mutations; DNA microarrays; proteomics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

systems biology endeavors to quantitatively describe the properties and dynamics of biological networks as a whole through the integration of …, …, …, and … information

A

genomic; transcriptomic; proteomic; metabolomic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

…: the overall process through which living systems acquire and use free energy to carry out their various functions

A

metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

…, or degradation, in which nutrients and cell constituents are broken down to salvage their components and/or to make energy available

A

catabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

…, or biosynthesis, in which biomolecules are synthesized from simpler components

A

anabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

in general, catabolic rxns carry out the … of nutrient molecules

A

exergonic oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

…, the intake and utilization of food; affects health, development, and performance

A

nutrition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

some prokaryotes are …, which can synthesize all their cellular constituents from simple molecules such as H2O, CO2, NH3, and H2S

A

autotrophs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

… obtain their energy through the oxidation of inorganic compounds such as NH3, H2S, or even Fe2+

A

chemolithotrophs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

… obtain energy via photosynthesis, a process in which light energy powers the transfer of electrons from inorganic donors to CO2 to produce carbohydrates, which are later oxidized to release free energy

A

photoautotrophs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

… obtain free energy through the oxidation of organic compounds (carbs, lipids, and proteins) and hence ultimately depend on … for those substances

A

heterotrophs; autotrophs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

… must use o2, whereas … employ oxidizing agents such as sulfate or nitrate

A

obligate aerobes; anaerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

…, such as E. coli, can grow in either the presence or the absence of O2. …, in contrast, are poisoned by the presence of O2.

A

facultative anaerobes; obligate anaerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

animals are obligate …, whose nutrition depends on a balanced intake of the … proteins, carbs, and lipids

A

aerobic heterotrophs; macronutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

the metabolic utilization of macronutrients also requires the intake of O2 and water, as well as … composed of … and …

A

micronutrients; vitamins; minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Vitamins can be divided into two groups: … vitamins and … vitamins

A

water-soluble; fat-soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q 
water-soluble vitamins: 
… 
…
 … 
… 
… 
… 
… 
… 
…
A 
biotin (b7_ 
pantothenic acid (B5_ 
cobalamin (B12)
riboflavin (b2)
nicotinamide (niacin; B3) 
pyridoxine (B6)
Folic acid (B9)
thiamine (B1)
ascorbic acid (C)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q 
fat-soluble vitamins: 
…
… 
… 
...
A

vit A
vit D
vit E
vit K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

the NAD+ component …, or its carboxylic acid analog .. (niaci), relieves the ultimately fatal dietary deficiency disease in humans known as pellagra

A

nicotinamide; nicotinic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

most animals, including humans, can synthesize nicotinamide from the amino acid …

A

tryptophan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

… are series of connected enzymatic rxns that produce specific products. their reactants, intermediates, and products are referred to as …

A

metabolic pathways; metabolites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

in degradative pathways, the major nutrients, referred to as …, are exergonically broken down into simpler products. the free energy released in the degradative process is conserved by synthesis of ATP, or by the reduction of a coenzyme such as NADP+

A

complex metabolites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

the pathways for the catabolism of a large number of diverse substances (carbs, lipids, and proteins) converge on a few …, in many cases a two carbon acetyl unit linked to coenzyme A, to form …

A

common intermediates; acetyl-coenzyme A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

when one substances is oxidized (loses e-), another must be … (gain 3-)

A

reduced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

relatively few … serve as starting materials for a host of varied products

A

metabolites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

rxns catalyzed by the six classes of enzymes
… and … (catalyzed by oxidoreductases)
… (catalyzed by transferases and hydrolases)
…
…
…. (catalyzed by isomerases and mutases)
reactions that … or … (catalyzed by hydrolases, lyases, and ligases)

A 
oxidations; reductions
group-transfer rxns
eliminations
isomerizations
rearrangements 
make or break C-C bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

electron transport and oxidative phosphorylation occur in the …, whereas glycolysis ( a carbohydrate degradation pathway) and fatty acid biosynthesis occur in the …

A

mitochondria; cytosol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

the synthesis of metabolites in specific membrane-bounded compartments in eukaryotic cells requires … to … these substances between compartments. accordingly, … are essential components of many metabolic processes

A

mechanisms; transport; transport proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

…: enzymes that catalyze the same rxn but are encoded by different genes and have different kinetic/regulatory properties

A

isozymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

example of isozyme:

vertebrates possess two homologs of the enzyme …, which catalyzes the interconversion of pyruvate and lactate

A

lactate dehydrogenase

46
Q

many metabolic rxns are said to be …, bc their delta g values are close to zero, and they can be relatively easily reversed by changing the ratio of products to reactants

A

near-equilibrium rxns

47
Q

enzymes that catalyze near-equilibrium rxns tend to act quickly to restore …, and the net rates of such rxns are effectively controlled by the relative concentrations of … and …

A

equilibrium concentrations; substrates; products

48
Q

for enzymes that work on rxns operating far from equilibrium, only changes in the … of the enzyme can significantly alter the rate. the enzyme controls the flow of substrate through the reaction by …, much as a dam controls the flow of a river by varying the opening of its floodgates

A

activity; varying its activity

49
Q

…: rate of flow of metabolites through a metabolic pathway

A

flux

50
Q

metabolic pathways are … –> a highly exergonic rxn is irreversible. if such a rxn is part of a multistep pathway, it confers … on the pathway; that is, it makes the entire pathway irreversible

A

irreversible; directionality

51
Q

every metabolic pathway has a first … –> although most rxns in a metabolic pathway function close to equilibriu, there is generally an irreversible rxn early in the pathway that commits its product to continue down the pathway

A

committed step

52
Q

… and … pathways differ

A

catabolic; anabolic

53
Q

the existence of independent interconversion routes is an important property of metabolic pathways bc it allows … of the two processes

A

independent control

54
Q

the flux of intermediates through a metabolic pathway in a steady state is more or less …; that is the rates of synthesis and breakdown of each pathway intermediate maintain it at a …

A

constant; constant concentration

55
Q

the flux of metabolites, J, through each rxn step is the rate of the forward rxn, vf, less that of the reverse rxn, vr:
…

A

J = vf - vr

56
Q

At equilibrium, by definition, there is no flux (J = 0), although vf and vr may be quite large. In reactions that are far from equilibrium, vf ≫ vr, the flux is essentially equal to the …

A

rate of the forward reaction (J ≈ vf).

57
Q

the rate determining step functions far from … and has a large negative …

A

equilibrium; free energy change

58
Q

(mechanisms to control flux through rate-determining steps)

  1. … control
  2. … modification (e.g. phosphorylation/dephosphorylation)
  3. …, where vf and vr may be independently varied
  4. … control
A

allosteric
covalent
substrate cycles
genetic

59
Q

a metabolic pathway is part of a … process

A

supply-demand

60
Q

Oxidative metabolism proceeds in a stepwise fashion, so the released free energy can be recovered in a manageable form at each exergonic step of the overall process. These “packets” of energy are conserved by the synthesis of a few types of … whose subsequent exergonic breakdown drives endergonic processes.

A

“high-energy” intermediates

61
Q

ATP consists of an … moiety (adenine + ribose) to which … groups are sequentially linked via .. bond followed by two … bonds

A

adenosine; three phosphoryl; a phosphoester; phosphoanhydride

62
Q

..: measure of the tendency of phosphorylated compounds to transfer their phosphoryl groups to water

A

phosphoryl group-transfer potentials

63
Q

a favorable free energy change for a rxn does not indicate how … the rxn occurs.

A

quickly

64
Q

(reasons for high energy character of phosphoanhydride bonds) . The resonance stabilization of a phosphoanhydride bond is less than that of its hydrolysis products. This is because a phosphoanhydride’s two strongly electron-withdrawing groups must compete for the lone pairs of electrons of its bridging oxygen atom, whereas this competition is absent in the hydrolysis products. In other words, the electronic requirements of the phosphoryl groups are less satisfi ed in a …than in its …

A

phosphoanhydride; hydrolysis products

65
Q

(reasons for high energy character of phosphoanhydride bonds) Of perhaps greater importance is the destabilizing effect of the ….between the charged groups of a phosphoanhydride compared to those of its hydrolysis products. In the physiological pH range, ATP has three to four negative charges whose mutual electrostatic repulsions are partially relieved by ATP hydrolysis.

A

electrostatic repulsions

66
Q

(reasons for high energy character of phosphoanhydride bonds) Another destabilizing influence, which is difficult to assess, is the smaller … of a phosphoanhydride compared to that of its hydrolysis products. Some estimates suggest that this factor provides the dominant thermodynamic driving force for the hydrolysis of phosphoanhydrides

A

solvation energy

67
Q

as long as the overall pathway is exergonic, it will …

A

operate in the forward direction

68
Q

the initial step in the metabolism of glucose is its conversion to …

A

glucose-6-phosophate

69
Q

atp can be regenerated by coupling its synthesis from ADP and Pi to the more exergonic cleavage of …

A

phosphoenolpyruvate

70
Q

…, the enzyme that catalyzes the formation of glucose-6-phosphate does not catalyze ATP hydrolysis but instead catalyzes the transfer of a phosphoryl group from ATP directly to glucose

A

hexokinase

71
Q

…, transfers a phosphoryl group from phosphoenolpyruvate to ADP to form ATP

A

pyruvate kinase

72
Q

in processes of ATP hydrolysis, proteins undergo conformational changes in response to binding ATP. the exergonic hydrolysis of ATP and release of ADP and Pi renders these changes … and thereby drives the processes forward

A

irreversible

73
Q

ATP hydrolysis is … favored but … disfavored

A

thermodynamically; kinetically

74
Q

although many rxns involve ATP yield ADP and Pi (…), others yield AMP and PPi (…)

A

orthophosphate cleavage; pyrophosphate cleavage

75
Q

the pyrophosphate cleavage of ATP ultimately consumes two

A

high energy phosphoanhydride bonds

76
Q

atp is continually being … and ..

A

hydrolyzed; regenerated

77
Q

atp itself can be regenerated by coupling its formation to a more

A

highly exergonic metabolic process

78
Q

other mechanisms generate ATP indirectly, using the energy supplied by transmembrane proton concentration gradients. in oxidative metabolism, this process is called … whereas in photosynthesis, it is termed …

A

oxidative phosphorylation; photophosphorylation

79
Q

…: enzymes that transfer phosphoryl groups from ATP to other compounds or from phosphorylated compounds to ADP

A

kinases

80
Q

muscle and nerve cells, which have a high ATP turnover, rely on … to regenerate ATP rapidly

A

phosphoguanidines

81
Q

the phosphorylation of creatine by creatine kinase is endergonic under standard conditions; however, the intracellular concentrations of its reactants and products are such that it operates

A

close to equilibrium

82
Q

… acts as an ATP “buffer” in cells that contain …

A

phosphocreatine; creatine kinase

83
Q

…: a phosphoguanidine whose phosphoryl group transfer potential is greater than that of ATP; these compounds can therefore phosphorylate ADP to generate ATP

A

phosphagen

84
Q

… are synthesized from ATP and the corresponding … in a rxn catalyzed by the nonspecific enzyme …:
ATP + NDP ADP + NTP

A

nucleoside triphosphates; nucleoside diphosphate; nucleoside diphosphate kinase

85
Q

the … bond is involved in substrate-level phosphorylation, an TP generating process that is independent of- and presumably arose before- oxidative phosphorylation

A

thioester

86
Q

… consists of a beta-mercaptoethylamine group bonded through an amide linkage to the vitamin … which is attached to a 3’-phosphoadenosine moiety via a pyrophosphate bridge (LOOK AT CELL MOLEC Q)

A

coenzyme A; pantothenic acid;

87
Q

CoA functions as a carrier of … and other … groups

A

acetyl; acyl

88
Q

a … or … agent is an electron donor

an … or … agent is an electron acceptor

A

reductant; reducing

oxidant; oxidizing

89
Q

redox rxns can be divided into two …

A

half-rxns

90
Q

a half rxn consists of an e… and its conjugate …

A

electron donor; electron acceptor

91
Q

the electron donor and conjugate electron acceptor constitue a … or … analogous to a conjugate acid-base pair

A

redox couple; conjugate redox pair

92
Q

the two half-rxns of a redox rxn, each consisting of a conjugate redox pair, can be physically separated to form an ..

A

.electrochemical cell

93
Q

….: the tendency for a substance to undergo reduction (gain electrons)

A

reduction potential

94
Q

…: electron pressure that the electrochemical cell exerts

A

electromotive force (emf)

95
Q

a positive electromotive force indicates a … rxn, one that can do work

A

spontaneous rxn

96
Q

the more positive the standard reduction potential, the higher the affinity of the redox couple’s oxidized form for …; that is, the greater the tendency for the redox couple’s oxidized form to … and thus become …

A

electrons; accept electrons; reduced

97
Q

the protein components of redox enzymes play active roles in … by modulating the … of their bound redox-active centers

A

electron-transfer rxns; reduction potentials

98
Q

NADH functions as an energy rich …

A

e- transfer coenzyme

99
Q

the oxidation by o2 of one NADH to NAD+ supplies sufficient free energy to generate almost …

A

3 ATPs

100
Q

a metabolic pathway can be understood in terms of the sequence of rxns by which a specific nutrient is … and the … of the conversions

A

converted to end products; energetics

101
Q

a metabolic pathway can be understood in terms of the mechanisms by which each intermediate is converted to its …

A

successor

102
Q

a metabolic pathway can be understood in terms of the … that regulate the flow of metabolites through the pathway

A

control mechanisms

103
Q

the fate of an isotopically labeled atom in a metabolite can be elucidated by following its progress through the

A

metabolic pathway of interest

104
Q

one way to perturb a pathway is to add certain substances, called …, that block the pathway at specific points, thereby causing the preceding intermediates to build up

A

metabolic inhibitors

105
Q

the basic metabolic pathways in most organisms are essentially

A

identical

106
Q

…: chemical agents that induce genetic changes

A

mutagens

107
Q

… the entire collection of RNA transcribed by a cell

A

transcriptome

108
Q

…: the complete set of proteins synthesized by a cell in response to changing conditions

A

proteome

109
Q

…: the cell’s collection of metabolic intermediates

A

metabolome

110
Q

… or … are made by depositing numerous diff DNA segments of known gene sequences in a precise array on a solid support such as a coated glass surface. these are often PCR-amplified cDNA clones derived from mRNAs

A

DNA microarrays; DNA chips

Biochem (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions