AP Biology : Cellular Respiration

Study concepts, example questions & explanations for AP Biology

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Example Questions

Example Question #41 : Cellular Respiration

Glycolysis takes place inside the cytoplasm of a cell. Which is not a product or reactant of this process?

Possible Answers:

Glucose

Oxygen

Pyruvate

ATP

All of the answer choices are involved in glycolysis.

Correct answer:

Oxygen

Explanation:

Oxygen is neither a product nor reactant in glycolysis. Glycolysis is unique in that it takes place within the cytoplasm of the cell and does not require oxygen. It is an anaerobic reaction that produces pyruvate, NAD, and ATP. Know the products and reactants of glycolysis.

Example Question #42 : Cellular Respiration

In cell respiration, glucose is converted to pyruvate in which of the following metabolic pathways?

Possible Answers:

Gluconeogenesis

Light dependent reaction

Krebs cycle

Oxidative phosphorylation

Glycolysis

Correct answer:

Glycolysis

Explanation:

The correct answer to this question is glycolysis.

We can know this if we remember that glycolysis is a ten step anaerobic, not aerobic pathway that uses the 6 carbon sugar known as glucose and converts it to 2 pyruvate molecules. All of the other answers do not use glucose and convert it to pyruvate. 

Example Question #43 : Cellular Respiration

Which of the following are not produced during the reactions of glycolysis?

Possible Answers:

ATP

NADH

Pyruvate

Carbon dioxide

Heat

Correct answer:

Carbon dioxide

Explanation:

The correct answer to this question is carbon dioxide.

Carbon dioxide is not produced during glycolysis. Remember in glycolysis one glucose molecule yields 2 pyruvate, 2 ATP, and 2 NADH. Heat is also given off in form of energy as we went over before. Carbon dioxide is involved in other processes.

Example Question #44 : Cellular Respiration

Which of the following processes occurs in the cytosol of a eukaryotic cell? 

Possible Answers:

Fermentation and chemiosmosis

Oxidative phosphorylation

Oxidation of pyruvate to acetyl-CoA

Glycolysis and fermentation

Citric acid cycle

Correct answer:

Glycolysis and fermentation

Explanation:

The correct answer to this question is glycolysis and fermentation.

Glycolysis and fermentation occur in the cytosol of a eukaryotic cell. Chemiosmosis occurs in the inner mitochondrial membrane and thylakoid membranes of chloroplasts in eukaryotes. The citric acid cycle occurs in the mitochondrial matrix. Oxidative phosphorylation occurs in the mitochondria so the answer has to be glycolysis and fermentation

Example Question #45 : Cellular Respiration

In comparison to fermentation, the aerobic pathway of glucose metabolism yields more of what?

Possible Answers:

Ammonium

ATP

Ethanol

Pyruvate

Acetaldehyde

Correct answer:

ATP

Explanation:

The correct answer to this question is ATP.

Fermentation is the metabolic process that takes place in anaerobic environments to regenerate  for glycolysis. ATP is the main product of cellular respiration and the molecular energy of the cell. The aerobic metabolism results in a very high yield of these energies because it can use oxygen as the final electron acceptor in the electron transport chain.

Example Question #46 : Cellular Respiration

In anaerobic conditions, pyruvate is converted into __________ in an effort to regenerate __________.

Possible Answers:

lactate . . . 

alcohol . . . 

lactate . . . ATP

lactate . . . carbon dioxide

Correct answer:

lactate . . . 

Explanation:

Anaerobic respiration occurs when there is not enough oxygen necessary for pyruvate to be shunted to the citric acid cycle. In the absence of oxygen, lactate is formed. The purpose of forming lactate is to also regenerate , as  can be used in a cyclical fashion to continue the process of cellular respiration. When oxygen supply returns, the pyruvate will be shunted away from the production of lactate and instead go to the citric acid cycle.

Example Question #47 : Cellular Respiration

Which of these processes occurs in both photosynthesis and respiration?

Possible Answers:

chemiosmosis

 

glycolysis

citric acid cycle

Calvin cycle

Krebs cycle

Correct answer:

chemiosmosis

 

Explanation:

Chemiosmosis is the coupling of the movement of electrons down the electron transport chain with the formation of ATP by utilizing the force of the proton gradient. Think about it this way, the creation of ATP is needed in both photosynthesis and respiration and this is why it is involved in both.

Example Question #48 : Cellular Respiration

Which of the following statements regarding glycolysis is correct?

Possible Answers:

glycolysis occurs in the cytoplasm

glycolysis leads to the production of 2 ATP, 1 NADH, and 2 pyruvate

glycolysis can occur only with oxygen

glycolysis involves the production of G5P or glucose-5-phosphate

glycolysis is the first step in anaerobic respiration but not aerobic respiration

Correct answer:

glycolysis occurs in the cytoplasm

Explanation:

The process of glycolysis indeed occurs in the cytoplasm. Answer 'glycolysis can occur only with oxygen' is incorrect, because glycolysis can actually occur with or without oxygen, due to oxygen playing no role in glycolysis.

Answer 'glycolysis is the first step in anaerobic respiration but not aerobic respiration' is incorrect, because glycolysis is simply the first step in BOTH anaerobic respiration and aerobic respiration.

Answer 'glycolysis leads to the production of 2 ATP, 1 NADH, and 2 pyruvate' is incorrect, because the end product of glycolysis is 2 NADH, not 1 NADH.

Answer 'glycolysis involves the production of G5P or glucose-5-phosphate' is incorrect, because glycolysis involves the production of G6P, not G5P.

Example Question #49 : Cellular Respiration

Why is the significance of lactic acid fermentation in anaerobic respiration? 

Possible Answers:

Since oxygen is no longer present to accept the electrons in the ETC, it provides an alternative path to make ATP. 

Lactic acid fermentation creates ATP.

Lactic acid fermentation gives a short term solution to the ATP crisis. 

Lactic acid fermentation uses up pyruvate.

Lactic acid fermentation replenishes NAD+ so that glycolysis can continue.

Correct answer:

Lactic acid fermentation replenishes NAD+ so that glycolysis can continue.

Explanation:

Since there is no more oxygen, we undergo anaerobic respiration, which in humans is lactic acid fermentation. Lactic acid does not produce any energy, so it doesn't solve the ATP crisis nor does it produce ATP. It is true that lactic acid fermentation does use up pyruvate, but so does the citric acid cycle. The importance is that lactic acid fermentation turns NADH into NAD+ so that it can be recycled into glycolysis to create ATP. 

Example Question #50 : Cellular Respiration

What causes muscle soreness? 

Possible Answers:

alcohol fermentation

lactic acid fermentation

reduction of glucose

aerobic respiration 

substrate level phosphorylation

Correct answer:

lactic acid fermentation

Explanation:

When the body isn't getting enough oxygen, it undergoes lactic acid fermentation. The purpose of lactic acid fermentation is so that your body can generate ATP through glycolysis by turning pyruvate into lactate and in the processes regenerating NAD+. Since lactate is poisonous, we eventually have to breathe. When oxygen combines with lactate it turns into lactic acid, which in turn causes muscle soreness. 

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