Chapter 5

Question 1

enzymes:
A) are biologic catalysts
B) are protein-containing compounds
C) lower the activation energy required for chemical reactions
D) work optimally at a specific pH
E) All of the answer choices are correct

Answer 1

E

Question 2

Working with yeast juice, _____________ discovered that an unstable substance in the
cozymase filtrate degraded sugar; the energizing substance contained the nitrogen-
containing compound adenine linked to the sugar ribose and three phosphate groups
now known as ATP.
A) Louis Pasteur
B) Claude Bouchard
C) Arthur Harden
D) Eduard Buchner
E) Karl Lohmann

Answer 2

E

Question 3

(n) ____________ is a substance that donates or loses electrons when oxidized.
A) substrate
B) enzyme
C) oxidizing agent
D) reducing agent

Answer 3

D

Question 4

The passive movement of molecules down their concentration gradient is known as:
A) osmosis
B) endocytosis
C) diffusion
D) coupled transport

Answer 4

C

Question 5

____ minimize change in H+ concentration.
A) acids
B) bases
C) buffers
D) neutralizers

Answer 5

C

Question 6

the chemical reactions of glycolysis:
A) require oxygen
B) do not require oxygen
C) produce large amounts of ATP
D) are essentially aerobic
E) cause the release of nitrogen

Answer 6

B

Question 6

________ is an oxidizing agent.
A) oxygen
B) hydrogen
C) NAD+
D) ATP
E) All of the answer choices are correct

Answer 6

A

Question 7

Freeing ________ atoms during the Krebs cycle is one of the most important chemical
events in energy metabolism.
A) nitrogen
B) carbon
C) oxygen
D) hydrogen

Answer 7

D

Question 7

________ provide anaerobic sources of phosphate-bond energy.
A) ADP and PCr
B) ADP, AMP, and PCr
C) ATP and PCr
D) ATP, ADP, AMP, and PCr

Answer 7

C

Question 8

Oxygen’s primary role in the aerobic resynthesis of ATP is as a(n):
A) reducing agent
B) oxidizing agent
C) proton acceptor
D) substrate
E) All of the answer choices are correc

Answer 8

B

Question 9

Aerobic energy from glucose catabolism occurs via the:
A) glycolytic pathway
B) gluconeogenic pathway
C) Cori cycle
D) Krebs cycle-electron transport pathway

Answer 9

D

Question 10

he first law of thermodynamics, as it related to physiologic systems, dictates that
energy is:
A) absorbed
B) consumed
C) produced
D) transformed

Answer 10

D

Question 11

Aerobic energy from glucose catabolism occurs via the:
A) glycolytic pathway
B) gluconeogenic pathway
C) Cori cycle
D) Krebs cycle-electron transport pathway

Answer 11

D

Question 12

ellular oxidation occurs at which of the following sites?
A) cytosol
B) sarcoplasmic reticulum
C) respiratory vacuole
D) cytoplasm
E) None of the answer choices are correct.

Answer 12

E

Question 13

The end product of aerobic glycolysis is:
A) lactate
B) acetyl-CoA
C) pyruvate
D) oxaloacetate

Answer 13

C

Question 14

Citrate is produced in the citric acid cycle when:
A) oxaloacetate combines with acetyl-CoA
B) pyruvate combines with coenzyme A
C) coenzyme A combines with oxaloacetate
D) pyruvate combines with oxaloacetate

Answer 14

A

Question 15

Substrate-level phosphorylation occurs:
A) only within the endoplasmic reticulum
B) only within the mitochondrion
C) only in glycolysis
D) in glycolysis and citric acid cycle metabolism

Answer 15

D

Question 16

net gain of _____ ATP molecules forms during substrate-level phosphorylation in
glycolysis:
A) 2
B) 4
C) 6
D) 36

Answer 16

A

Question 17

Which of the following statements about carbohydrate is TRUE?
A) It is the only macronutrient whose stored energy is used to regenerate ATP
aerobically.
B) It supplies about one-quarter of the body’s energy requirements during heavy
exercise.
C) It serves as a metabolic primer for protein breakdown.
D) Processing fat for energy through the metabolic mill requires some carbohydrate
catabolism.
E) All of the answer choices are true

Answer 17

D

Question 18

A rate-limiting glycolytic enzyme is:
A) amylase
B) oxidative kinase
C) aldolase
D) phosphofructokinase
E) lactate kinase

Answer 18

D

Question 19

Which of the following are components of aerobic metabolism?
A) citric acid cycle
B) electron transport
C) oxidative phosphorylation
D) citric acid cycle and electron transport
E) citric acid cycle, electron transport, and oxidative phosphorylatio

Answer 19

E

Question 20

Degrading complex organic molecules to simpler form is called:
A) anabolism
B) condensation
C) hydrolysis
D) reduction
E) oxidation

Answer 20

C

Question 21

The location of the biochemical substrate converted to a chemically different product is
the:
A) coenzyme activation site
B) enzyme active site
C) proton conservation site
D) substrate-product complex site
E) None of the answer choices are correct

Answer 21

B

Question 22

True or false? Glucose cannot form from the 2-carbon acetyl fragments from -
oxidation of fatty acids.
A) True
B) False

Answer 22

TRUE

Question 23

true or false? Reduction involves a loss of electrons.
A) True
B) False

Answer 23

TRUE

Question 24

True or false? Diffusion is an energy-requiring process.
A) True
B) False

Answer 24

FALSE

Question 25

rue or false? Direct calorimetry involves the biopsy of small tissue fragments.
A) True
B) False

Answer 25

FALSE

Question 25

rue or false? Pyruvate plus 2 hydrogen atoms produces oxaloacetate.
A) True
B) False

Answer 25

FALSE

Question 26

True or false? FAD acts as a reducing agent.
A) True
B) False

Answer 26

FALSE

Question 27

True or false? Lactic acid formation is an irreversible chemical reaction.
A) True
B) False

Answer 27

FALSE