Deck 5: Cellular Respiration

Question 1

What is the final product of glycolysis?

A) fructose
B) glyceraldehyde-3-phosphate
C) pyruvate
D) glucose

Answer 1

C

Question 2

Which statement best describes the function of NADH and FADH₂?

A) Both produce ATP by substrate-level phosphorylation.
B) Both transport acetyl-CoA to mitochondria.
C) Both provide electrons to the electron transport system.
D) Both release energy for glycolysis to proceed.

Answer 2

C

Question 3

Glycolysis can take place in the absence of which of the following small molecules?

A) FAD
B) ATP
C) NAD⁺
D) ADP

Answer 3

A

Question 4

Which molecules are responsible for delivering the high-energy electrons from the citric acid cycle to the electron transfer system?

A) Cyt C and Q
B) NADH and Cyt C
C) FADH₂ and Q
D) NADH and FADH₂

Question 5

Which cellular respiration process is absolutely dependent upon a supply of NADH?

A) glycolysis
B) the electron transfer system
C) pyruvate oxidation
D) the citric acid cycle

Question 6

Ultimately, the carbon molecules in pyruvate become integrated into which of the following molecules?

A) CoA
B) ATP
C) CO₂
D) acetate

Question 7

What is the final product of glycolysis?

A) 1 molecule of pyruvate
B) 2 molecules of pyruvate
C) 1 molecule of glyceraldehyde-3-phosphate
D) 2 molecules of glyceraldehyde-3-phosphate

Question 8

For a molecule to be reduced, it can gain electrons from the environment. In what other way can a molecule be reduced?

A) by losing hydrogens
B) by losing oxygen
C) by gaining oxygen
D) by gaining hydrogens

Question 9

Which of these processes actually produces a significant quantity of ATP during cellular respiration?

A) pyruvate oxidation
B) glycolysis
C) oxidative phosphorylation
D) the citric acid cycle

Question 10

Which of these chemical reactions are common in cellular respiration?

A) reduction/oxidation
B) bimolecular/trimolecular
C) exothermic/endothermic
D) acid/base

Question 11

What molecule is a product of each of glycolysis, pyruvate oxidation, and the citric acid cycle?

A) ATP
B) FADH₂
C) NADH
D) H₂O

Question 12

During which stage of cellular respiration is CO₂ released?

A) during the citric acid cycle
B) during glycolysis
C) during electron transport system
D) during both pyruvate oxidation and the citric acid cycle

Question 13

Which chemical characteristic makes phosphoenolpyruvate (PEP) unusual?

A) PEP regulates the activity of phosphofructokinase.
B) PEP can carry out redox reactions.
C) PEP provides high-energy electrons to make ATP.
D) PEP supplies a high-energy phosphate to phosphorylate ADP.

Question 14

It has been thought that many human diseases are now associated with malfunctioning mitochondria. Why are the mitochondria so important to all cells?

A) They generate heat to keep the body warm.
B) They produce energy in the form of ATP.
C) They are extremely large.
D) They are ancestral and were acquired by symbiosis.

Question 15

In the process of aerobic metabolism, carbon-containing molecules are broken down. What is the energy from the electrons used for?

A) to generate a proton gradient
B) to heat the organism in a cold environment
C) to alter enzyme structure
D) to directly supply the energy needs of an organism

Question 16

Which of these statements best explains why food is not energy?

A) Energy is exhaustive, and food is not.
B) Food is exhaustive, and energy is not.
C) Food can make us fat, and energy cannot.
D) Energy can make us fat, and food cannot.

Question 17

Which of the following is the best line of evidence for glycolysis being an ancient pathway?

A) Glycolysis occurs in mitochondria.
B) Glycolysis is universal.
C) Glycolysis is highly regulated.
D) Glycolysis is complicated.

Question 18

Glycolysis can take place in the absence of which of the following small molecules?

A) ATP
B) oxygen
C) NAD⁺
D) ADP

Question 19

If glycolysis is considered universal, which of the following illustrates that?

A) Glycolysis occurs in Archaea, Bacteria, and Eukarya.
B) Glycolysis occurs in Archaea and Eukarya.
C) Glycolysis occurs in Bacteria and Eukarya.
D) Glycolysis occurs in Archaea and Bacteria.

Question 20

Which of these statements best explains the energetic status of cellular respiration?

A) It is an exergonic process with negative free energy.
B) It is an endergonic process with negative free energy.
C) It is an exergonic process with positive free energy.
D) It is an endergonic process with positive free energy.

Question 21

Suppose that the pH of the matrix was significantly lower than the inner mitochondrial space. How would ATP synthase function differently?

A) It would stop functioning.
B) It would function with less efficiency.
C) It would require an ion to stabilize it.
D) It would hydrolyze ATP to form ADP.

Question 22

Which phrase best describes the proton-motive force?

A) the amount of energy required to protonate a glucose molecule
B) the force needed to move protons into the inner mitochondrial space
C) the free energy associated with the removal of hydrogen from NADH
D) the combination of a proton and voltage gradient across the membrane

Question 23

Which part of the ATP synthase is responsible for catalyzing ATP formation?

A) the basal unit
B) the stalk
C) the headpiece
D) the lollipop-shaped complex

Question 24

Where is ATP synthase located in eukaryotic cells?

A) in the matrix of the mitochondria
B) in the outer membrane of the cell
C) in the nuclear envelope
D) in the inner mitochondrial membrane

Question 25

For every glucose molecule that goes through cellular respiration, how many times is a carbon molecule fully oxidized to CO₂ in the citric acid cycle?

A) 4 times
B) 3 times
C) 2 times
D) 1 time

Question 26

Which piece of the ATP synthase contains the channel for H⁺ to flow through?

A) the stalk
B) the basal unit
C) the headpiece
D) the lollipop-shaped complex

Question 27

Which phrase best describes what occurs during chemiosmosis?

A) the synthesis of ATP by ATP synthase using energy from the proton gradient
B) the buildup of acetate in the cytoplasm in the absence of oxygen
C) the breakdown of oxygen as it enters the mitochondria
D) the production of NADH and FADH₂ in cellular respiration

Question 28

What is the proton-motive force used for?

A) only to drive rotation of flagella in eukaryotes
B) only for ATP synthesis in bacteria
C) ATP synthesis and driving rotation of flagella in bacteria
D) ATP synthesis and driving rotation of flagella in eukaryotes

Question 29

Suppose that the proton gradient was destroyed and ATP was no longer produced by oxidative phosphorylation. Which statement describes what happens to these protons as they re-enter the mitochondrial matrix?

A) They help in the production of CO₂.
B) They are attached to NAD⁺ and FAD.
C) They synthesize ATP by substrate-level phosphorylation.
D) They combine with oxygen to form water.

Question 30

Which phrase describes the mechanism that facilitates the passage of electrons between protein complexes in the mitochondrial inner membrane?

A) The oxidized electron carrier protein passes on the electron to FADH and becomes reduced.
B) The reduced electron carrier protein passes on the electron to the next protein and becomes oxidized.
C) The reduced electron carrier protein passes on the electron to FADH and becomes oxidized.
D)The oxidized electron carrier protein passes on the electron to the next protein and becomes reduced.

Question 31

What are the functions of cytochrome c and ubiquinone?

A) They shuttle electrons between the protein complexes.
B) They synthesize water from molecular oxygen.
C) They translocate protons from the matrix to the inner mitochondrial space.
D) They produce ATP by substrate-level phosphorylation.

Question 32

Oxygen acts as a final electron acceptor in respiration. Which molecule is it ultimately converted into?

A) water
B) CO₂
C) ATP
D) glucose

Question 33

What is the purpose of the last stage of the citric acid cycle?

A) to replenish the supplies of NAD⁺ and FAD
B) to break down glucose into a three-carbon molecule
C) to regenerate oxaloacetate to attach to another acetyl molecule
D) to produce ATP by substrate-level phosphorylation

Question 34

Which of the following molecules is responsible for carrying the acetyl group from pyruvate into the citric acid cycle?

A) FADH₂
B) ATP
C) CoA
D) NADH

Question 35

Which of the following directly powers the ATP synthase?

A) carbohydrate metabolism
B) NADH/FADH₂
C) the proton gradient
D) electron transfer

Question 36

Which of the following directly supply the electrons to the electron transport system?

A) FADH₂ and NADH
B) pyruvate and acetate
C) ATP and ADP
D) complexes I to IV

Question 37

Where do the electrons that ubiquinone accepts come from?

A) complexes I and II
B) complexes I and III
C) complexes II and III
D) complexes III and IV

Question 38

Which phrase best describes the chemical conditions inside the mitochondrial matrix?

A) low pH and high pyruvate concentration
B) high pH and high pyruvate concentration
C) high pH and low pyruvate concentration
D) low pH and low pyruvate concentration

Question 39

What is the fate of CoA after it delivers an acetyl group into the citric acid cycle?

A) It is used in protein synthesis.
B) It remains in an inactive form until the cell dies.
C) It is degraded and used for energy.
D) It is recharged with another acetate.

Question 40

Which of the following are directly responsible for pumping protons out of the matrix in the mitochondria?

A) cytochrome c, ubiquinone, and protein complex II
B) cytochrome c, and protein complexes I and III
C) protein complexes I, III, and IV
D) ubiquinone, and protein complexes I and IV

Question 41

Glycolysis takes place in the mitochondria of a cells.

Question 42

Refer to the illustration of a mitochondrion. Match the labelled parts of the mitochondrion with the steps of cellular respiration. A labelled part may be used once, more than once, or not at all.
a.outer mitochondrial membrane
b.intermembrane compartment
c.cytosol
d.inner mitochondrial membrane
e.matrix
oxidative phosphorylation

Question 43

Suppose it is true that potato plants use uncoupling proteins in a way similar to how mammals use them. What would a researcher expect to observe in these plants?

A) increased amounts of ATP production
B) decreased mitochondrial catabolism
C) increased internal tissue temperature
D) decreased sugar metabolism

Question 44

During pyruvate oxidation, one molecule of ATP is produced.

Question 45

Both plants and animals possess mitochondria, which are used for cellular respiration to make ATP.

Question 46

The main purpose of fermentation is to regenerate NADH and FADH₂.

Question 47

Molecular oxygen gets into the body through breathing and leaves the body as carbon dioxide.

Question 48

How efficient is cellular respiration in extracting the energy stored in the bonds of glucose?

A) close to 60% efficient
B) close to 40% efficient
C) close to 20% efficient
D) close to 10% efficient

Question 49

Refer to the illustration of a mitochondrion. Match the labelled parts of the mitochondrion with the steps of cellular respiration. A labelled part may be used once, more than once, or not at all.
a.outer mitochondrial membrane
b.intermembrane compartment
c.cytosol
d.inner mitochondrial membrane
e.matrix
pyruvate oxidation

Question 50

Consider the contribution of NADH and FADH₂. How many of the 32 total ATP molecules produced in cellular respiration come from oxidative phosphorylation?

A) 20
B) 22
C) 28
D) 30

Question 51

Which of the following best illustrates the concept of supply and demand in cells?

A) Fatty acids can be used as a source of energy by being reduced to acetyl-CoA
B) Fatty acids can be used as a source of energy by being oxidized to acetyl-CoA
C) Fatty acids can be used as a source of energy by being oxidized to acetyl-CoA
D) Fatty acids can be used as a source of energy by being reduced to acetyl-CoA

Question 52

If, during a chemical reaction, a molecule loses hydrogens, it could be described as being oxidized.

Question 53

Refer to the illustration of a mitochondrion. Match the labelled parts of the mitochondrion with the steps of cellular respiration. A labelled part may be used once, more than once, or not at all.
a.outer mitochondrial membrane
b.intermembrane compartment
c.cytosol
d.inner mitochondrial membrane
e.matrix
citric acid cycle

Question 54

Refer to the illustration of a mitochondrion. Match the labelled parts of the mitochondrion with the steps of cellular respiration. A labelled part may be used once, more than once, or not at all.
a.outer mitochondrial membrane
b.intermembrane compartment
c.cytosol
d.inner mitochondrial membrane
e.matrix
ATP synthesis

Question 55

During the process of pyruvate oxidation, pyruvate is broken down and the remaining two carbons are attached to coenzyme A.

Question 56

During glycolysis, ATP is produced by oxidative phosphorylation.

Question 57

Two mobile electron carriers that are important for the electron transport system are cytochrome c and ubiquinone.

Question 58

Refer to the illustration of a mitochondrion. Match the labelled parts of the mitochondrion with the steps of cellular respiration. A labelled part may be used once, more than once, or not at all.
a.outer mitochondrial membrane
b.intermembrane compartment
c.cytosol
d.inner mitochondrial membrane
e.matrix
glycolysis

Question 59

Why do cells go through fermentation in our body?

A) to replenish NAD⁺
B) to replenish O₂
C) to replenish FAD
D) to replenish NADH

Question 60

Which of these analogies best illustrates the following: Sugars contain energy, but we have to break them apart to release the energy in order to make the high energy chemical called ATP.

A) electrons of matter
B) photons of light
C) letters in a word
D) books in a library

Question 61

Refer to the illustration of a mitochondrion. Match the labelled parts of the mitochondrion with the steps of cellular respiration. A labelled part may be used once, more than once, or not at all.
a.outer mitochondrial membrane
b.intermembrane compartment
c.cytosol
d.inner mitochondrial membrane
e.matrix
electron transfer system