Lesson 4: Energy and Metabolism

Question 1

The main purpose of the fermentation pathway is to ________ when oxygen is absent.

A. generate ATP
B. maintain a pool of oxidized NAD+
C. maintain a pool of reduced NADH
D. provide an alternative fuel to glucose, in the form of 
     alcohol,
E. drive the citric acid cycle

Answer 1

B. maintain a pool of oxidized NAD+

Question 2

Which of the following normally occurs regardless of whether or not oxygen (O) is present?

A. oxidative phosphorylation (chemiosmosis)
B. oxidation of pyruvate to acetyl CoA
C. citric acid cycle
D. glycolysis
E. fermentation

Answer 2

D. glycolysis

Question 3

During intense exercise, as skeletal muscle cells go into anaerobiosis, the human body will increase its catabolism of

A. carbohydrates only.
B. proteins only.
C. fats only.
D. fats, carbohydrates, and proteins.
E. fats and proteins only.

Answer 3

A. carbohydrates only.

Question 4

Approximately how many molecules of ATP are produced from the complete oxidation of two molecules of glucose (C6H12O) in aerobic cellular respiration?

A. 15
B. 30-32
C. 2
D. 4
E. 60-64

Answer 4

E. 60-64

Question 5

Chemiosmotic ATP synthesis (oxidative phosphorylation) occurs in

A. all cells, but only in the presence of oxygen.
B. only in mitochondria, using either oxygen or other
electron acceptors.
C. all cells, in the absence of respiration.
D. all respiring cells, both prokaryotic and eukaryotic,
using either oxygen or other electron acceptors.
E. only eukaryotic cells, in the presence of oxygen.

Answer 5

D. all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors.

Question 6

Which of the following is a statement of the first law of thermodynamics?

A. Energy cannot be transferred or transformed.
B. The entropy of the universe is constant.
C. Kinetic energy is stored energy that results from the
specific arrangement of matter.
D. Energy cannot be created or destroyed.
E. The entropy of the universe is decreasing.

Answer 6

D. Energy cannot be created or destroyed.

Question 7

Use the following information to answer the questions below.

Exposing inner mitochondrial membranes to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal “inside out.” These little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. If the membranes are agitated further, however, the ability to synthesize ATP is lost.
After the further agitation of the membrane vesicles, what must be lost from the membrane?

A. the prosthetic groups like heme from the transport
system
B. ATP synthase, in whole or in part
C. the contact required between inner and outer
membrane surfaces
D. the ability of NADH to transfer electrons to the first
acceptor in the electron transport chain
E. cytochromes

Answer 7

B. ATP synthase, in whole or in part

Question 8

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of

A. a reaction with a positive ΔG.
B. active transport.
C. osmosis.
D. an endergonic reaction coupled to an exergonic 
     reaction.
E. allosteric regulation.

Answer 8

D. an endergonic reaction coupled to an exergonic reaction.

Question 9

When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell?

A. The phosphate may be incorporated into any
molecule that contains phosphate.
B. The phosphate can be added to water and excreted
as a liquid.
C. The phosphate can only be used to regenerate
more ATP.
D. The phosphate is released as an excretory waste.
E. It enters the nucleus to affect gene expression.

Answer 9

A. The phosphate may be incorporated into any molecule that contains phosphate.

Question 10

Which of the following statements is a logical consequence of the second law of thermodynamics?

A. Every chemical reaction must increase the total
entropy of the universe.
B. If there is an increase in the energy of a system,
there must be a corresponding decrease in the
energy of the rest of the universe.
C. Every energy transfer requires activation energy
from the environment.
D. If the entropy of a system increases, there must be a
corresponding decrease in the entropy of the
universe.
E. Energy can be transferred or transformed, but it
cannot be created or destroyed.

Answer 10

A. Every chemical reaction must increase the total entropy of the universe.

Question 11

One function of both alcohol fermentation and lactic acid fermentation is to

A. reduce NAD+ to NADH.
B. reduce FAD+ to FADH2.
C. reduce FADH2 to FAD+.
D. oxidize NADH to NAD+.
E. do none of the above.

Answer 11

D. oxidize NADH to NAD+.

Question 12

Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction’s

A. free-energy content.
B. activation energy.
C. entropy.
D. endothermic level.
E. equilibrium point.

Answer 12

B. activation energy.

Question 13

The ATP made during glycolysis is generated by

A. oxidation of NADH to NAD+.
B. substrate-level phosphorylation.
C. photophosphorylation.
D. chemiosmosis.
E. electron transport.

Answer 13

B. substrate-level phosphorylation.

Question 14

In order to attach a particular amino acid to the tRNA molecule that will transport it, an enzyme, an aminoacyl-tRNA synthetase, is required, along with ATP. Initially, the enzyme has an active site for ATP and another for the amino acid, but it is not able to attach the tRNA. What must occur in order for the final attachment to occur?

A. The ATP must be hydrolyzed to allow the amino acid
to bind to the synthetase.
B. The ATP must first have to attach to the tRNA.
C. The binding of the first two molecules must cause a
3-D change that opens another active site on the
enzyme.
D. The 3’ end of the tRNA must have to be cleaved
before it can have an attached amino acid.
E. The tRNA molecule must have to alter its shape in
order to be able to fit into the active site with the
other two molecules.

Answer 14

C. The binding of the first two molecules must cause a 3-D change that opens another active site on the enzyme.

Question 15

In glycolysis, for each molecule of glucose oxidized to pyruvate

A. two molecules of ATP are used and two molecules
of ATP are produced.
B. six molecules of ATP are used and six molecules of
ATP are produced.
C. two molecules of ATP are used and four molecules
of ATP are produced.
D. four molecules of ATP are used and two molecules
of ATP are produced.
E. two molecules of ATP are used and six molecules of
ATP are produced.

Answer 15

C. two molecules of ATP are used and four molecules of ATP are produced.

Question 16

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

A. catabolism
B. catalysis
C. dehydration
D. metabolism
E. anabolism

Answer 16

A. catabolism

Question 17

Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to

A. form cleavage furrows during cell division.
B. extend pseudopods.
C. separate chromosomes during cell division.
D. maintain the shape of the nucleus.
E. migrate by amoeboid movement.

Answer 17

C. separate chromosomes during cell division.

Question 18

Which of the following statements is correct about diffusion?

A. It is very rapid over long distances.
B. It is a passive process in which molecules move
from a region of higher concentration to a region of
lower concentration.
C. It is an active process in which molecules move from
a region of lower concentration to one of higher
concentration.
D. It requires integral proteins in the cell membrane.
E. It requires an expenditure of energy by the cell.

Answer 18

B. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

Question 19

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean?

A. Cells of each domain evolved proton pumps
independently when oceans became more acidic.
B. Proton pumps must have evolved before any living
organisms were present on Earth.
C. Proton gradients across a membrane were used by
cells that were the common ancestor of all three
domains of life.
D. Proton pumps are necessary to all cell membranes.
E. The high concentration of protons in the ancient
atmosphere must have necessitated a pump
mechanism.

Answer 19

C. Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.

Question 20

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean?

A. Cells of each domain evolved proton pumps
independently when oceans became more acidic.
B. Proton pumps must have evolved before any living
organisms were present on Earth.
C. Proton gradients across a membrane were used by
cells that were the common ancestor of all three
domains of life.
D. Proton pumps are necessary to all cell membranes.
E. The high concentration of protons in the ancient
the atmosphere must have necessitated a pump
mechanism.

Answer 20

C. Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.