Deck 14: Introduction to Metabolism

Question 1

Consider the following metabolic reaction:
Succinyl-CoA + Acetoacetate $\rarr$ Acetoacetyl-CoA + Succinate $\Delta$ G°' = -1.25 kJ/mol
What is the K_eq for this reaction at 25°C?

A)1.66
B)0.602
C)1.00
D)4.22 x 10²
E)3.21

Answer 1

1.66

Question 2

Matching
Prokaryotes that are able to synthesize all of their cellular components from simple molecules such as CO₂, H₂O, NH₃, and H₂S are called ______.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Answer 2

autotrophs

Question 3

Consider the following metabolic reaction:
2-Phosphoglycerate $\rarr$ 3-Phosphoglycerate $\Delta$ G°' = −4.40 kJ/mol
What can be said about this reaction when the concentration of 2-phosphoglycerate is 0.490 mM and the concentration of 3-phosphoglycerate is 2.90 mM at 25°C?
I.This reaction is endergonic under these conditions.
II.This reaction is exergonic under these conditions.
III.This reaction is at equilibrium under these conditions.
IV.This reaction is not favorable under standard conditions.

A)I, IV
B)II only
C)III only
D)IV only
E)None of the above

Answer 3

III only

Question 4

Consider the following metabolic reaction:
Succinyl-CoA + Acetoacetate $\rarr$ Acetoacetyl-CoA + Succinate $\Delta$ G°' = -1.25 kJ/mol
This reaction is

A)favorable under standard conditions.
B)not favorable under standard conditions.
C)nonspontaneous as written regardless of reactant concentrations
D)spontaneous as written only when [succinate] and [acetoacetyl-CoA] are high.
E)favorability of this reaction as written depends on temperature and reactant concentrations

Question 5

Given that the standard reduction potential of oxaloacetate is -0.166 V and the standard reduction potential of NAD⁺ is -0.315 V.What is the $\Delta$$\epsilon$ °' for the oxidation of malate by NAD⁺:
Malate + NAD⁺ $\rarr$ Oxaloacetate + NADH + H⁺

A)-4.81 V
B)+ 4.81 V
C)-0.149 V
D)+0.149 V
E)+0.052 V

Question 6

Matching
The standard reduction potential under biochemical standard state conditions is symbolized as ______.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Question 7

Which of the numbered arrows in the figure points toward a high-energy phosphoanhydride bond?

A)1
B)2
C)3
D)4
E)5

Question 8

Matching
A metabolic reaction resulting in the formation of FADH₂ is an example of a(n)___ reaction.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Question 9

Which of the choices correctly ranks the following compounds from lowest level of oxidation to highest level of oxidation?

A)1< 2< 3
B)2< 1< 3
C)1< 3< 2
D)3< 2< 1
E)2< 3< 1

Question 10

Matching
The enzyme ______ catalyzes the transfer of a phosphoryl group from ATP to AMP.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Question 11

Consider the following metabolic reaction: Succinyl-CoA + Acetoacetate $\rarr$ Acetoacetyl-CoA + Succinate $\Delta$ G°' = -1.25 kJ/mol
The $\Delta$ G°' for the hydrolysis of Succinyl-CoA is -33.9 kJ/mol.What is the $\Delta$ G°' for the hydrolysis of Acetoacetyl-CoA: Acetoacetyl-CoA $\rarr$ Acetoacetate + CoA

A)-35.2 kJ/mol
B)-32.7 kJ/mol
C)+32.7 kJ/mol
D)+35.2 kJ/mol
E)none of the above

Question 12

Matching
Organisms that require oxygen for nutrient breakdown are called ______.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Question 13

Matching
The study of the complete set of proteins synthesized in the cell in response to changing conditions is called ______.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Question 14

The K_eq is 0.503 at 25°C for the following reaction.What is the $\Delta$ G°' for this reaction?
D-Glucose-6-phosphate $\rarr$ D-Fructose-6-phosphate $\Delta$ G°'= ?

A)-2.87 × 10³ J/mol
B)+1.70 kJ/mol
C)+143 J/mol
D)The $\Delta$ G°' cannot be determined with the given information.
E)The $\Delta$ G°' can be determined with the given information but the correct answer is not shown.

Question 15

Matching

-The enzyme ______ catalyzes the reaction, PP_i $\rarr$ 2 P_i.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Question 16

Matching

-The reaction NADH $\rarr$ NAD⁺ is an example of _____.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Question 17

Matching
Biomolecules are synthesized from simpler components in ______ pathways.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Question 18

Organisms that can grow in either the presence or absence of oxygen are classified as

A)obligate aerobes
B)facultative anaerobes
C)autotrophs
D)heterotrophs
E)obligate anaerobes

Question 19

Consider the following metabolic reaction:
3-Phosphoglycerate $\rarr$ 2-Phosphoglycerate $\Delta$ G°' = +4.40 kJ/mol
What is the $\Delta$ G for this reaction when the concentration of 2-phosphoglycerate is 0.290 mM and the concentration of 3-phosphoglycerate is 2.90 mM at 37°C?

A)+10.3 kJ/mol
B)-1.53 kJ/mol
C)-1.30 kJ/mol
D)-5.93 kJ/mol
E)-4.40 kJ/mol

Question 20

Matching
1,3-Bisphosphoglycerate is an example of a(n)______.

A)anabolic
B)adenylate kinase
C)
D)catabolic
E)phosphorylase kinase
F)obligate aerobes
G)acyl phosphate
H)proteomics
I)reduction
J)pyrophosphatase
K)autotrophs
L)oxidation
M)ΔG°’

Question 21

Which compound is in the highest oxidation state?

A)carbon monoxide
B)carbon dioxide
C)ethanol
D)A, B, and C are equal
E)A and B are equal

Question 22

The conversion of triacylglycerides into fatty acids for the purpose of energy generation is an example of which of the following?

A)heterotropism
B)anaerobism
C)catabolism
D)anabolism
E)glycolysis

Question 23

Which of the following is (are)true regarding vitamins?
I.They are essential organic molecules an organism is unable to synthesize.
II.Some water soluble vitamins mediate electron-transfer reactions.
III.In humans, the water soluble vitamins converted into organic coenzymes.
IV.In humans, the fat soluble vitamins mediate group transfer reactions.

A)I, II, III, IV
B)I, II, III
C)II, III, IV
D)I only
E)II, IV

Question 24

In eukaryotes, glycolysis typically occurs in the

A)mitochondrion.
B)cytosol.
C)lysosome.
D)rough endoplasmic reticulum.
E)smooth endoplasmic reticulum.

Question 25

______ is the most reliable systems biology approach to assess gene expression.

A)genomics
B)transcriptomics
C)proteomics
D)metabolmics
E)none of the above

Question 26

The enzyme inorganic pyrophosphatase catalyzes the hydrolysis of bonds in ___.

A)ATP
B)ADP
C)AMP
D)PP_i
E)phosphate

Question 27

In the catabolic pathway major nutrients are _________ broken down resulting in the synthesis of __________ .

A)exergonically; ADP
B)endergonically; ADP
C)exergonically; ATP
D)endergonically; NADP⁺
E)endergonically; ATP

Question 28

In redox half-reactions, a more positive standard reduction potential means
I.the oxidized form has a higher affinity for electrons.
II.the oxidized form has a lower affinity for electrons.
III.the reduced form has a higher affinity for electrons.
IV.the greater the tendency for the oxidized form to accept electrons.

A)I only
B)II only
C)II, III
D)I, IV
E)II, IV

Question 29

While ____ is always involved in reactions that require the transfer of 2 electrons, ____ can participate in reactions that transfer either 1 or 2 electrons.

A)O₂; NAD⁺
B)NAD⁺; FAD
C)NAD⁺; O₂
D)flavin; niacin
E)FAD; NAD⁺

Question 30

The ______ is equal to the rate of synthesis minus the rate of breakdown of the metabolic intermediates.

A)metabolic rate
B)K_eq
C)rate determining step
D)flux
E)none of the above

Question 31

Obligate aerobes

A)perish under conditions with O₂.
B)use oxidizing agents such as sulfate or nitrate as a primary food source.
C)resemble the earliest life forms.
D)all of the above
E)none of the above

Question 32

ATP contains ________ bonds.

A)one phosphoanhydride and two phosphoester
B)two phosphoester and one glycosidic
C)three phosphoanhydride
D)one amide and three phosphoanhydride
E)one phosphoester and two phosphoanhydride

Question 33

The term "Nutrition" involves which of the following components?
I.food intake
II.metabolic utilization of food
III.the intake requirement of oxygen
IV.the control of metabolic flux

A)I only
B)II only
C)I, II
D)I, II, III
E)I, II, III, IV

Question 34

Cells control or regulate the flux through metabolic pathways by means of
I.allosteric control of enzymes.
II.covalent modification of enzymes.
III.genetic control of the concentrations of enzymes.
IV.genetic expression of allosteric effectors.

A)I, II, III, IV
B)II, III
C)I, II, IV
D)I, II, III
E)I, IV

Question 35

The vitamin ______ is one of the components of coenzyme A, which is involved in _____.

A)pantothenic acid; carboxylation
B)pantothenic acid; acyl transfer
C)cobalamin; acyl transfer
D)riboflavin; carboxylation
E)niacin; electron transfer

Question 36

Consider the following metabolic reaction important in muscle and nerve cells:
ATP + creatine $\rightleftarrows$ phosphocreatine + ADP $\Delta$ G°' = +12.6 kJ/mol
Under intracellular conditions, the $\Delta$ G for the reaction, which is catalyzed by the enzyme creatine kinase, is ~0 kJ/mol.From this information we can conclude that

A)creatine kinase catalysis would not be necessary under intracellular conditions.
B)ATP has a greater phosphoryl group transfer potential compared to phosphocreatine.
C)at equilibrium, most intracellular creatine is phosphorylated.
D)the reaction operates close to equilibrium in cells.
E)None of the above is a correct conclusion.

Question 37

Acetyl-CoA contains a ____ bond which often provides the energy required for substrate-level phosphorylation.

A)phosphoester
B)phosphoanhydride
C)phosphothioester
D)ester
E)thioester

Question 38

Acyl phosphates such as 1,3-bisphosphoglycerate have a ______ phosphoryl group transfer potential compared to ATP, which can be recognized by the _______ $\Delta$ G°' values for hydrolysis.

A)greater; more positive
B)greater; more negative
C)lower; more positive
D)lower; more negative
E)none of the above

Question 39

The terminal electron acceptor in an aerobic organisms is

A)CO₂.
B)NAD⁺.
C)FAD.
D)O₂.
E)H₂O.

Question 40

Which of the following are factors that contribute to the large negative standard free energy change for the reaction shown below?
ATP $\rarr$ ADP + P_i

A)the increase in resonance stabilization in the reactants compare to the products
B)the precipitation of the insoluble P_i
C)the addition of a water molecule to the hydrophilic ATP molecule
D)the decrease in negative charge repulsion in the products compared to reactants
E)all of the above

Question 41

Use the table below to rank the redox centers in order of increasing ability to produce a favorable electron flow.

A)D, Q, F, C, Z
B)Q, F, C, D, Z
C)Z, Q, F, C, D
D)Z, F, C, D, Q
E)Z, Q, C, Q, D

Question 42

Negative feedback inhibition is one type of _______ metabolic control.

A)allosteric
B)hormonal
C)covalent modification
D)genetic
E)signal transduction

Question 43

If the diagram below represents a catabolic pathway, and enzyme 1 requires NAD⁺, what type of reaction does enzyme 1 catalyze?

A)reduction
B)oxidation
C)isomerization
D)any of the above
E)none of the above

Question 44

A researcher is interested in determining if a long term change in the carbohydrate content of an individual's diet alters the levels of expression of carbohydrate metabolizing enzymes.Which of the following would address this question?

A)proteomics
B)DNA microarrays
C)genomics
D)lipidomics
E)none of the above

Question 45

What are the correct coenzyme forms that correspond to X and Y in the following reaction as catalyzed by lactate dehydrogenase?
Pyruvate + X → Lactate + Y

A)X = NADH , Y = NAD⁺
B)X = NADPH , Y = NADP⁺
C)X = NAD⁺ , Y = NADH
D)X = FAD , Y = FADH₂
E)X = NADH , Y = NADP⁺

Question 46

Which of the following increase the phosphate transfer potential of compound?
I.electrostatic repulsion between charged groups on the reactant
II.resonance stabilization of the hydrolysis products
III.greater energy of solvation of the hydrolysis products
IV.the presence of a enol group in the reactants

A)I, II
B)I, IV
C)I, II, IV
D)II, IV
E)I, II, III, IV

Question 47

Compound "K" is the ultimate product of a linear metabolic pathway consisting of ten enzymatically catalyzed reactions as shown below.

Complete the following description.
If "K" inhibits activity of enzyme "5", then enzyme "5" is under ___ control.If enzyme "3" becomes activated in response to activity of protein kinase A only when compound "A" is present, then enzyme "3" is under ___ control.If enzyme "2" is only expressed in the presence of high concentrations of "A," then enzyme "2" is under ___ control.If all of these are true, high concentrations of "__" will decrease the flux through the pathway.

A)covalent modification; allosteric; genetic; A
B)allosteric; covalent modification; genetic; K
C)genetic; allosteric; genetic; K
D)allosteric; genetic; genetic; K
E)allosteric; genetic; genetic; A

Question 48

Identify the structure pictured below.

A)NAD⁺
B)NADH
C)FAD
D)FADH₂
E)Coenzyme A (CoA)

Question 49

What type of metabolic control is described in the figure below?

A)feed forward activation
B)product Inhibition
C)feedback Inhibition
D)hormonal control
E)signal transduction control

Question 50

NADH is a derivative of

A)niacin.
B)riboflavin.
C)lipoic acid.
D)thiamine.
E)vitamin A.

Question 51

If Z = ATP formed via substrate level phosphorylation in the diagram below, which of the following compounds (represented by an uppercase letter)contains a high-energy bond?

A)Compound A
B)Compound B
C)Compound C
D)All have equally high energy.
E)All have equally low energy.

Question 52

I have discovered a new metabolic enzyme which utilizes NAD⁺ as a coenzyme.Which of the following could be true based on this information?

A)It is involved in a catabolic pathway.
B)It is involved in an anabolic pathway.
C)It performs acyl group transfer.
D)It catalyzes a hydrolytic cleavage.
E)It catalyzes the reduction of the enzyme's substrate.