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

10. Which of the following is not a component of the electron transport chain?

  1. NADH dehydrogenase

  2. Ubiquinone

  3. Cytochrome c reductase

  4. ATP synthase
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

ATP synthase is not a component of the electron transport chain, but it is involved in the final step of oxidative phosphorylation, where ATP is synthesized.

Multiple choice

12. What is the name of the process by which electrons are transferred from NADH and FADH2 to the electron transport chain?

  1. Oxidative phosphorylation

  2. Electron transfer

  3. Glycolysis

  4. Krebs cycle
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Electron transfer is the process by which electrons are transferred from NADH and FADH2 to the electron transport chain.

Multiple choice

13. What is the name of the molecule that carries electrons from complex III to complex IV in the electron transport chain?

  1. NADH

  2. Ubiquinone

  3. Cytochrome c

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

Cytochrome c is the molecule that carries electrons from complex III to complex IV in the electron transport chain.

Multiple choice

14. Which of the following is not a consequence of the electron transport chain?

  1. Generation of ATP

  2. Production of NADH and FADH2

  3. Release of carbon dioxide

  4. Generation of a proton gradient
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The release of carbon dioxide is not a consequence of the electron transport chain.

Multiple choice

15. What is the name of the enzyme complex that catalyzes the transfer of electrons from ubiquinone to cytochrome c?

  1. NADH dehydrogenase

  2. Ubiquinone reductase

  3. Cytochrome c reductase

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

Cytochrome c reductase is the enzyme complex that catalyzes the transfer of electrons from ubiquinone to cytochrome c.

Multiple choice

Which of the following is NOT a type of amino acid catabolism?

  1. Transamination

  2. Oxidative deamination

  3. Decarboxylation

  4. Glycolysis
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Glycolysis is not a type of amino acid catabolism. It is a metabolic pathway that breaks down glucose to generate energy.

Multiple choice

Which enzyme catalyzes the oxidative deamination of glutamate?

  1. Glutamate dehydrogenase

  2. Glutamate transaminase

  3. Glutamate decarboxylase

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

Glutamate dehydrogenase catalyzes the oxidative deamination of glutamate, converting it to α-ketoglutarate and ammonia.

Multiple choice

What is the name of the cycle that converts glutamate to α-ketoglutarate?

  1. Krebs cycle

  2. Glycolysis

  3. Glutamate-α-ketoglutarate cycle

  4. Pentose phosphate pathway
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The glutamate-α-ketoglutarate cycle is a metabolic pathway that converts glutamate to α-ketoglutarate, which can then be further oxidized in the citric acid cycle to generate energy.

Multiple choice

What are enzymes?

  1. Proteins that speed up chemical reactions

  2. Carbohydrates that provide energy for cells

  3. Lipids that form cell membranes

  4. Nucleic acids that store genetic information
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Enzymes are proteins that act as catalysts in biochemical reactions, increasing the rate of the reaction without being consumed in the process.

Multiple choice

What is the role of enzymes in biochemical reactions?

  1. To increase the activation energy of the reaction

  2. To decrease the activation energy of the reaction

  3. To change the products of the reaction

  4. To change the reactants of the reaction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Enzymes decrease the activation energy of a reaction by providing an alternative pathway for the reaction to occur, allowing it to proceed more quickly.

Multiple choice

What is the substrate of an enzyme?

  1. The molecule that the enzyme binds to

  2. The molecule that the enzyme catalyzes the reaction of

  3. The molecule that is produced by the enzyme-catalyzed reaction

  4. The molecule that is consumed by the enzyme-catalyzed reaction
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The substrate of an enzyme is the molecule that the enzyme catalyzes the reaction of.

Multiple choice

What are the factors that affect enzyme activity?

  1. Temperature

  2. pH

  3. Substrate concentration

  4. Enzyme concentration

  5. All of the above
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Enzyme activity is affected by a number of factors, including temperature, pH, substrate concentration, and enzyme concentration.

Multiple choice

What is enzyme inhibition?

  1. The process of increasing enzyme activity

  2. The process of decreasing enzyme activity

  3. The process of changing the substrate of an enzyme

  4. The process of changing the product of an enzyme
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Enzyme inhibition is the process of decreasing enzyme activity.

Multiple choice

Which of the following is NOT a type of enzyme?

  1. Oxidoreductases

  2. Transferases

  3. Hydrolases

  4. Ligases
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ligases are not a type of enzyme, but rather a type of enzyme that catalyzes the formation of new covalent bonds between two molecules.

Multiple choice

What is the primary function of glycolysis in cellular respiration?

  1. Generation of ATP

  2. Production of NADH and FADH2

  3. Breakdown of glucose

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

Glycolysis serves multiple purposes in cellular respiration. It breaks down glucose, generates ATP, and produces NADH and FADH2, which are essential electron carriers for the electron transport chain.