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

Which of the following statements is/are true regarding Entner–Doudoroff pathway?

  1. It is an alternate series of reactions that catabolise glucose to pyruvate.
  2. Occurs both in prokaryotes as well as eukaryotes.
  3. Has a net yield of 2 ATP for every glucose molecule metabolised.

  1. Only 1

  2. Only 2

  3. Only 3

  4. 1 and 2

  5. 2 and 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Entner–Doudoroff pathway is an alternate series of reactions that catabolise glucose to pyruvate using a set of enzymes different from those used in glycolysis or pentose phosphate pathway.

Multiple choice

Which one of the following acts as C3 convertase in this particular pathway?

The alternative pathway of complement activation is triggered when a breakdown product of C3 hydrolysis, C3b is deposited on the surface of a microbe. Next step in this pathway is to form C3 convertase which enzymatically breaks down more C3.

  1. C3bBb

  2. C3bBbC3b

  3. C3a

  4. C4b2a

  5. C1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

C3bBb. The microbe-bounded C3b becomes substrate for the binding of another protein called Factor B, which is broken down by a plasma membrane to generate the Bb fragment. This fragment remain attached to C3b and the resulting C3bBb acts as C3 convertase in alternative pathway.

Multiple choice

Which of the following compound stabilize C3 convertase in this alternative pathway?

The alternative pathway of complement activation is triggered when a breakdown product of C3 hydrolysis, C3b is deposited on the surface of a microbe. Next step in this pathway is to form C3 convertase which enzymatically breaks down more C3.

  1. Factor D

  2. Properdin

  3. Histamine

  4. Cytokine

  5. Integrin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Properdine stabilizes the C3 convertase on microbial surface.

Multiple choice

Glyconeogenesis is the process of ___________.

  1. formation of glycogen from glucose

  2. breakdown of glycogen into glucose

  3. formation of glucose from fatty acids, fats or proteins

  4. formation of glycogen from fatty acids, fats or proteins

  5. formation of pyruvic acid from glucose
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The process of formation of glycogen from fatty acids, fats or proteins is called glyconeogenesis.

Multiple choice

Which of the following statements is/are correct?

a. Respiration breaks food by oxidising it and releasing energy. b. Energy produced during respiration is stored in ADP molecules. c. ADP cells have a high energy content.

  1. a, b and c

  2. a and b

  3. a and c

  4. b and c

  5. a only
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct answer. Respiration includes breathing and oxidation of food in the cells. It breaks food by oxidising it and releasing energy.

Multiple choice

Acetyl Co A is produced from pyruvate by:

  1. oxidative hydrogenation

  2. oxidative phosphorespiration

  3. oxidative decarboxylation

  4. oxidative photophosphorylation

  5. oxidative phosphorylation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Oxidative decarboxylation results in the conversion of pyruvate into Acetyl Co A.

Multiple choice

Citric acid cycle is the alternative name of:

  1. Calvin cycle

  2. HMP shunt

  3. ETS

  4. Glycolysis

  5. TCA cycle
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Tricaboxylic acid cycle is also called citric acid cycle, which results in the complete oxidation of pyruvate into CO2 and H2O.

Multiple choice

Nitrate reductase enzyme forms

  1. nitrogen

  2. amino acid

  3. ammonia

  4. nitrite

  5. nitrate
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Nitrate reductse catalyse the conversion of nitrates into nitrites.