Biology

Cellular Respiration and Enzymes

1,721 Questions

Explore key concepts of cellular respiration, including glycolysis, the Krebs cycle, and the electron transport chain. These questions also cover ATP production, anaerobic respiration, and essential metabolic pathways. This topic forms a core part of the biology syllabus for many competitive examinations.

Glycolysis and metabolic pathwaysKrebs cycle processesElectron transport chainATP production countAnaerobic respiration products

Cellular Respiration and Enzymes Questions

Multiple choice

What is the name of the enzyme that catalyzes the conversion of 3-phosphoglycerate to 2-phosphoglycerate?

  1. Phosphoglyceromutase

  2. Enolase

  3. Pyruvate kinase

  4. Lactate dehydrogenase
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Phosphoglyceromutase catalyzes the conversion of 3-phosphoglycerate to 2-phosphoglycerate. This reaction is necessary for the continuation of glycolysis.

Multiple choice

Which of the following is NOT a product of the conversion of one molecule of glucose to two molecules of pyruvate?

  1. 2 molecules of ATP

  2. 2 molecules of NADH

  3. 2 molecules of FADH2

  4. 2 molecules of CO2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

FADH2 is not a product of the conversion of one molecule of glucose to two molecules of pyruvate. FADH2 is a product of the citric acid cycle, which occurs after glycolysis.

Multiple choice

Which bioinformatics approach is used to analyze the metabolic pathways and small molecules in a cell or tissue?

  1. Metabolomics

  2. Lipidomics

  3. Proteomics

  4. Transcriptomics
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Metabolomics is the study of the metabolic pathways and small molecules in a cell or tissue, providing insights into cellular processes and disease mechanisms.

Multiple choice

What is the primary function of oxidative phosphorylation in cellular respiration?

  1. To generate ATP molecules

  2. To produce NADH and FADH2

  3. To transport electrons across the mitochondrial membrane

  4. To release carbon dioxide as a waste product
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Oxidative phosphorylation is the final stage of cellular respiration, where the energy released from the oxidation of glucose is used to synthesize ATP molecules.

Multiple choice

What is the role of the electron transport chain in oxidative phosphorylation?

  1. To transfer electrons from NADH and FADH2 to oxygen

  2. To generate a proton gradient across the mitochondrial membrane

  3. To synthesize ATP molecules

  4. To produce water as a byproduct
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The electron transport chain is responsible for transferring electrons from NADH and FADH2 to oxygen, creating a proton gradient across the mitochondrial membrane.

Multiple choice

What is the function of ATP synthase in oxidative phosphorylation?

  1. To generate a proton gradient across the mitochondrial membrane

  2. To transfer electrons from NADH and FADH2 to oxygen

  3. To synthesize ATP molecules

  4. To produce water as a byproduct
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

ATP synthase uses the proton gradient generated by the electron transport chain to synthesize ATP molecules from ADP and inorganic phosphate.

Multiple choice

What is the chemiosmotic theory of oxidative phosphorylation?

  1. A theory that explains how the electron transport chain generates a proton gradient across the mitochondrial membrane

  2. A theory that explains how ATP synthase uses the proton gradient to synthesize ATP

  3. A theory that explains how oxidative phosphorylation is coupled to the synthesis of ATP

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The chemiosmotic theory of oxidative phosphorylation explains how the electron transport chain generates a proton gradient, how ATP synthase uses the proton gradient to synthesize ATP, and how these processes are coupled to produce ATP.

Multiple choice

Which of the following is a component of the electron transport chain?

  1. NADH dehydrogenase

  2. Cytochrome c

  3. ATP synthase

  4. FADH2 dehydrogenase
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

NADH dehydrogenase, cytochrome c, and FADH2 dehydrogenase are all components of the electron transport chain.

Multiple choice

What is the role of oxygen in oxidative phosphorylation?

  1. To accept electrons from the electron transport chain

  2. To generate a proton gradient across the mitochondrial membrane

  3. To synthesize ATP molecules

  4. To produce water as a byproduct
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Oxygen is the final electron acceptor in the electron transport chain, receiving electrons from cytochrome c oxidase.

Multiple choice

What is the name of the molecule that is reduced to form water in oxidative phosphorylation?

  1. NADH

  2. FADH2

  3. Oxygen

  4. Cytochrome c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Oxygen is reduced to form water in oxidative phosphorylation.

Multiple choice

How many ATP molecules are produced per molecule of glucose during oxidative phosphorylation?

  1. 36

  2. 38

  3. 40

  4. 42
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Approximately 36 ATP molecules are produced per molecule of glucose during oxidative phosphorylation.

Multiple choice

Which of the following is an inhibitor of oxidative phosphorylation?

  1. Cyanide

  2. Carbon monoxide

  3. Oligomycin

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cyanide, carbon monoxide, and oligomycin are all inhibitors of oxidative phosphorylation.

Multiple choice

What is the significance of oxidative phosphorylation in cellular respiration?

  1. It is the final stage of cellular respiration

  2. It generates the majority of ATP molecules in cellular respiration

  3. It is the only stage of cellular respiration that produces ATP

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Oxidative phosphorylation is the final stage of cellular respiration, generates the majority of ATP molecules in cellular respiration, and is the only stage that produces ATP.

Multiple choice

What is the role of NADH and FADH2 in oxidative phosphorylation?

  1. To donate electrons to the electron transport chain

  2. To generate a proton gradient across the mitochondrial membrane

  3. To synthesize ATP molecules

  4. To produce water as a byproduct
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

NADH and FADH2 donate electrons to the electron transport chain, which is necessary for the generation of a proton gradient and the synthesis of ATP.

Multiple choice

What is the name of the enzyme that catalyzes the synthesis of ATP in oxidative phosphorylation?

  1. ATP synthase

  2. NADH dehydrogenase

  3. Cytochrome c oxidase

  4. FADH2 dehydrogenase
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

ATP synthase is the enzyme that catalyzes the synthesis of ATP in oxidative phosphorylation.