Cellular Respiration

Question 1

What is the first step in cellular respiration?

Answer 1

Glycolysis

Question 2

What occurs during Glycolysis?

Answer 2

Breaks the glucose molecule into two molecules of pyruvate.
Generates 2 net ATP’s.
Occurs on the outside of the mitochondria.
Does not require not oxygen.
It is anaerobic.

Question 3

What is the second step in cellular respiration?

Answer 3

The Krebb Cycle.

Question 4

What occurs during the Krebb Cycle?

Answer 4

It is aerobic, produces 2 ATPs.
Also known as the citric acid cycle.
Produces NADH and FADH2 for the electron transport chain.

Question 5

What is the third step in cellular respiration?

Answer 5

Electron Transport Chain

Question 6

What occurs during the electron transport train?

Answer 6

Produces the bulk of the ATPs. 34 are produced in this specific stage but there is a total of 38 in perfect case scenario;
It is aerobic.
Electron carriers are reduced during glycolysis and the citric acid cycle to NADH, FADH2 and H+. These carriers then donate electrons and protons to the electron transport chain.
The final electron acceptor is oxygen.

Question 7

The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction

Answer 7

loses electrons and loses potential energy.

Question 8

Which of the following statements describes the results of this reaction?
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy
A) C6H12O6 is oxidized and O2 is reduced.
B) O2 is oxidized and H2O is reduced.
C) CO2 is reduced and O2 is oxidized.
D) C6H12O6 is reduced and CO2 is oxidized.
E) O2 is reduced and CO2 is oxidized.

Answer 8

A) C6H12O6 is oxidized and O2 is reduced.

Question 9

When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes

Answer 9

Reduced

Question 10

Which of the following statements describes NAD+?
A) NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle.
B) NAD+ has more chemical energy than NADH.
C) NAD+ is oxidized by the action of hydrogenases.
D) NAD+ can donate electrons for use in oxidative phosphorylation.
E) In the absence of NAD+, glycolysis can still function.

Answer 10

A) NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle.

Question 11

Where does glycolysis take place in eukaryotic cells?

Answer 11

Cytosol

Question 12

The ATP made during glycolysis is generated by

Answer 12

substrate-level phosphorylation.

Question 13

The oxygen consumed during cellular respiration is involved directly in which process or event?

Answer 13

accepting electrons at the end of the electron transport chain

Question 14

During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, most of the potential energy contained in
glucose is

Answer 14

retained in the two pyruvates

Question 15

In addition to ATP, what are the end products of glycolysis?

Answer 15

NADH and pyruvate

Question 16

Starting with one molecule of glucose, the energy-containing products of glycolysis are

Answer 16

2 NADH, 2 pyruvate, and 2 ATP

Question 17

In glycolysis, for each molecule of glucose oxidized to pyruvate

Answer 17

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

Question 18

Why is glycolysis described as having an investment phase and a payoff phase?

Answer 18

t uses stored ATP and then forms a net increase in ATP.

Question 19

Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2)
from one molecule of pyruvate?
A) lactate
B) glyceraldehydes-3-phosphate
C) oxaloacetate
D) acetyl CoA
E) citrate

Answer 19

D) acetyl CoA

Question 20

During cellular respiration, acetyl CoA accumulates in which location?

Answer 20

Mitochondrial matrix

Question 21

Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?
A) glycolysis and the oxidation of pyruvate to acetyl CoA
B) oxidation of pyruvate to acetyl CoA and the citric acid cycle
C) the citric acid cycle and oxidative phosphorylation
D) oxidative phosphorylation and fermentation
E) fermentation and glycolysis

Answer 21

B) oxidation of pyruvate to acetyl CoA and the citric acid cycle

Question 22

The primary role of oxygen in cellular respiration is to

Answer 22

act as an acceptor for electrons and hydrogen, forming water.

Question 23

Inside an active mitochondrion, most electrons follow which pathway?
A) glycolysis → NADH → oxidative phosphorylation → ATP → oxygen
B) citric acid cycle → FADH2 → electron transport chain → ATP
C) electron transport chain → citric acid cycle → ATP → oxygen
D) pyruvate → citric acid cycle → ATP → NADH → oxygen
E) citric acid cycle → NADH → electron transport chain → oxygen

Answer 23

E) citric acid cycle → NADH → electron transport chain → oxygen

Question 24

When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the
result is the

Answer 24

creation of a proton-motive force.

Question 25

Where is ATP synthase located in the mitochondrion?

Answer 25

inner membrane

Question 26

What is proton-motive force?

Answer 26

the force exerted on a proton by a transmembrane proton concentration gradient

Question 27

Which of the following normally occurs regardless of whether or not oxygen (O2) is present?
A) glycolysis
B) fermentation
C) oxidation of pyruvate to acetyl CoA
D) citric acid cycle
E) oxidative phosphorylation (chemiosmosis)

Answer 27

glycolysis

Question 28

Which of the following occurs in the cytosol of a eukaryotic cell?
A) glycolysis and fermentation
B) fermentation and chemiosmosis
C) oxidation of pyruvate to acetyl CoA
D) citric acid cycle
E) oxidative phosphorylation

Answer 28

A) glycolysis and fermentation

Question 29

Which metabolic pathway is common to both cellular respiration and fermentation?

Answer 29

glycolysis

Question 30

In alcohol fermentation, NAD+ is regenerated from NADH by

Answer 30

reduction of acetaldehyde to ethanol (ethyl alcohol).

Question 31

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

Answer 31

oxidize NADH to NAD+

Question 32

Which process produced both NADH and FADH2?

Answer 32

the citric acid cycle

Question 33

What establishes the electrochemical gradient across a membrane to provide energy for ATP production?

Answer 33

Hydrogen ions are pumped across the membrane by carrier proteins

Question 34

The reactions of pyruvate oxidation break:

Answer 34

pyruvates into acetyl-CoA and carbon dioxide

Question 35

Which organelles contain functioning ATP synthase complexes in their membranes?

Answer 35

mitochondria and chloroplasts

Question 36

Which of these processes is/are anaerobic?
A) fermentation
B) citric acid cycle
C) glycolysis
D) both A and B
E) both A and C

Answer 36

E) both A and C

Question 37

Which process produces alcohol in yeast or lactate in humans?
A) the citric acid cycle
B) glycolysis
C) the electron transport system
D) fermentation
E) pyruvate oxidation

Answer 37

D) fermentation