Chapter 13

Question 0

Glycolysis is an anaerobic process used to catabolism glucose. What does it mean for this process to be anaerobic?

1. No oxygen is required
2. No oxidation occurs
3. It takes place in the lysosome
4. Glucose is broken down by the addition of electrons

Answer 0

No oxygen is required

Question 1

Which of the following stages in the breakdown of the piece of toast you had for breakfast generates the most ATP?

1. The digestion of starch to glucose
2. Glycolysis
3. The citric acid cycle
4. Oxidative phosphorylation

Answer 1

Oxidative phosphorylation

Question 2

The advantage to the cell of gradual oxidation of glucose during cellular respiration compared with it’s combustion to CO2 and H2O in a single step is that _____.

1. More free energy is released for a given amount of glucose oxidized
2. No energy is lost as heat
3. Energy can be extracted in usable amounts
4. More CO2 is produced for a given amount of glucose oxidized

Answer 2

Energy can be extracted in usable amounts

Question 3

Which type of simple subunits listed below is used preferentially as an energy source?

1. Simple sugars
2. Proteins
3. Free fatty acids
4. Glycerol

Answer 3

Simple sugars

Question 4

The final metabolite produced by glycolysis is _______.

1. Acetyl CoA
2. Pyruvate
3. 3-phosphoglycerate
4. Glyceraldehyde 3-phosphate

Answer 4

Pyruvate

Question 5

Glycolysis generates more stored energy than it expends. What is the net number of activated carrier molecules produced in this process?

1. 6 ATP, 2NADH
2. 4 ATP, 4 NADH
3. 2 ATP, 2 NADH
4. 4 ATP, 2 NADH

Answer 5

2 ATP, 2 NADH

Question 6

Which of the following steps or processes in aerobic respiration include the production of carbon dioxide?

1. Breakdown of glycogen
2. Glycolysis
3. Conversion of pyruvate to acetyl CoA
4. Oxidative phosphorylation

Answer 6

Conversion of pyruvate to acetyl CoA

Question 7

I’m step 4 of glycolysis, a 6 carbon sugar is cleaved to produce 2 three carbon molecules. Which enzyme catalyzes this reaction?

1. Adolase
2. Phosphoglucose isomerase
3. Enolase
4. Triosephosphate isomerase

Answer 7

Aldolase

Question 8

The conversion of glyceraldehyde 3-phosphate to 1,3 biphosphoglycerate in step 6 of glycolysis generates a high energy phosphosnhydride bond. Which of the following best describes what happens to that bond I’m step 7?

1. It is hydrolized to drive the formation of ATP
2. It is hydrolized to drive the formation of NADH
3. It is hydrolized to generate pyruvate
4. It is oxidized to CO2

Answer 8

It is hydrolyzed to drive the formation of ATP

Question 9

Steps 7 and 10 of glycolysis result in substrate level phosphorylation. Which of the following best describes this process?

1. ATP is being hydrolyzed to phosphorylate the substrate.
2. The energy derived from substrate oxidation is coupled to the conversion of ADP to ATP
3. Two successive phosphates are transferred, first to AMP, then to ADP, finally forming ATP
4. The substrate is hydrolyzed using ATP as an energy source

Answer 9

Answer 2

Question 10

Which of the following descriptions best matches the function of a kinase?

1. An enzyme that catalyzes the rearrangement of bonds within a single molecule
2. An enzyme that catalyzes a change in the position of a specific chemical group within a single molecule.
3. An enzyme that catalyzes the oxidation of a molecule by removing a hydride ion.
4. An enzyme that catalyzes the addition of phosphate groups to other molecules.

Answer 10

An enzyme that catalyzes the addition of phosphate groups to other molecules.

Question 11

Which of the following descriptions best match the function of an isomerase?

1. An enzyme that catalyzes the rearrangement of bonds within a single molecule.
2. An enzyme that catalyzes a change in the position of a specific chemical group within a single molecule
3. An enzyme that catalyzes the oxidation of a molecule by removing a hydride ion
4. An enzyme that catalyzes the addition of phosphate groups to other molecules.

Answer 11

An enzyme that catalyzes the rearrangement of bonds within a single molecule

Question 12

Which of the following descriptions best matches the function of a mutase?

1. An enzyme that catalyzes the rearrangement of bonds within a single molecule.
2. An enzyme that catalyzes a change in the position of a specific chemical group within a single molecule.
3. An enzyme that catalyzes the oxidation of a molecule by removing a hydride ion
4. An enzyme that catalyzes the addition of phosphate groups to other molecules.

Answer 12

Answer 2

Question 13

Which of the following descriptions best matches the function of a dehydrogenase?

1. An enzyme that catalyzes the rearrangement of bonds within a single molecule.
2. An enzyme that catalyzes a change in the position of a specific chemical group within a single molecule.
3. An enzyme that catalyzes the oxidation of a molecule by removing a hydride ion
4. An enzyme that catalyzes the addition of phosphate groups to other molecules.

Answer 13

An enzyme that catalyzes the oxidation of a molecule by removing a hydride ion.

Question 14

On a diet consisting of nothing but protein, which of the following is the most likely outcome?

1. Loss of weight because amino acids cannot be used for the synthesis of fat
2. Muscle gain because the amino acids will go directly into building muscle.
3. Tiredness because amino acids cannot be used to generate energy
4. Excretion of more nitrogenous wastes than with a more balanced diet.

Answer 14

Excretion of more nitrogenous wastes

Question 15

Which of the following processes do not take place in the mitochondria?

1. Citric acid cycle
2. Conversion of pyruvate to activated acetyl groups
3. Oxidation of fatty acids to acetyl CoA
4. Glycogen breakdown

Answer 15

Glycogen breakdown

Question 16

Which reaction does the enzyme phosphoglucose isomerase catalyze?

1. Glucose —-> glucose 6 phosphate
2. Fructose 6 phosphate —–> fructose 1,6 biohosphate
3. Glucose 6 phosphate —-> fructose 6 phosphate
4. Glucose —-> glucose 1 phosphate

Answer 16

Answer 3

Question 17

What purpose does the phosphorylation of glucose to glucose 6 phosphate by the enzyme hexokinase serve as the first step in glycolysis?

1. It helps drive the uptake of glucose from outside the cell
2. If generates a high energy phosphate bond.
3. It converts ATP to a more useful form
4. It enables the glucose 6 phosphate to be recognized by Phosphofructokinase, the next enzyme in the glycolytic pathway.

Answer 17

It helps drives the uptake of glucose from outside the cell

Question 18

which of the following cells rely exclusively on glycolysis to supply tem with ATP?

1. Anaerobically growing yeast
2. Aerobic bacteria
3. Skeletal muscles cells
4. Plant cells

Answer 18

Anaerobically growing yeast

Question 19

In anaerobic conditions, skeletal muscle produces ______.

1. Lactate and CO2
2. Ethanol and CO2
3. Lactate only
4. Ethanol only

Answer 19

Lactate only

Question 20

Fermentation is a/an _______ process that concerts ________ into carbon dioxide and _______.

1. Anaerobic, pyruvate, ethanol
2. Anaerobic, lactate, ethanol
3. Eukaryotic, glyceraldehyde 3 phosphate, ethanol
4. Prokaryotic, lactate, propanol

Answer 20

Anaerobic, pyruvate, ethanol

Question 21

Glyceraldehyde 3 phosphate dehydrogenase operates by stripping a hydride ion from it’s substrate. Which molecule is the recipient of the proton and two electrons during this transfer?

1. Oxygen
2. Acetyl CoA
3. NAD+
4. FADH

Answer 21

NAD+

Question 22

How many different enzymes and what total number of polypeptides are required to perform this oxidation process in the mitochondrion?

1. 1;60
2. 3;3
3. 3;26
4. 3;60

Answer 22

3;60

Question 23

Which of the following statements about acetyl CoA is true?

1. Amino acids can be converted into acetyl CoA
2. Pyruvate is converted into acetyl CoA in the cytosol
3. Triacylglycerol molecules are transported into mitochondrial matrix and cleaved by lipases to produce acetyl CoA.
4. Oxaloacetate is converted directly into acetyl CoA to feed the citric acid cycle

Answer 23

Amino acids can be converted into acetyl CoA

Question 24

The reaction cycle that uses acetyl CoA to generate electron carrier molecules needed in the electron transport chain is important for powering the cell. Which of the names below is not one of those commonly used to describe this reaction cycle?

1. Tricarboxylic acid cycle
2. Keeps cycle
3. Oxaloacetic acid cycle
4. Citric acid cycle

Answer 24

Oxaloacetic acid cycle

Question 25

The citric acid cycle is a series of oxidation reactions that removes carbon atoms from substrates in the form of CO2. Where do the oxygen atoms in the carbon dioxide molecules come from?

1. Water
2. Phosphates
3. Molecular oxygen
4. Acetyl CoA

Answer 25

Water

Question 26

Once a molecule of acetyl CoA enters the citric acid cycle, how many complete cycles are required for both of the carbon atoms in it’s acetyl group to be oxidized to CO2?

1. 1
2. 2
3. 3
4. 4

Answer 26

4

Question 27

In step 1 of the citric acid cycle, citrate is generated by the enzyme citrate synthase. The enzyme combines the two carbon acetyl group from acetyl CoA and the four carbon oxaloacetate. What is the source of energy that drives this reaction forward?

1. A high energy phosphodiester bond
2. A transfer of high energy electrons
3. A high energy thioester bond
4. The heat of a molecular collision

Answer 27

A high energy thioester bond