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

Enzyme involved in glycolysis, which catalyzes the transfer of a phosphate group from phosphoenolpyruvate to ADP is ________.

  1. pyruvate dehydrogenase

  2. pyruvate kinase

  3. pyruvate carboxylase

  4. glucose 6-phosphatase

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

Pyruvate kinase is an enzyme involved in glycolysis. It catalyzes the transfer of a phosphate group from phosphoenolpyruvate (PEP) to ADP, yielding one molecule of pyruvate and one molecule of ATP.

Multiple choice

Uric acid is the end product of

  1. purine metabolism

  2. fat metabolism

  3. protein metabolism

  4. alcohol metabolism

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 Uric acid is the end product of purine metabolism.

Multiple choice

Urea is formed by which cycle?

  1. Kreb's cycle

  2. Ornithine cycle

  3. Calvin cycle

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

It is also called as the urea cycle which occurs in liver.

Multiple choice

Which enzyme uses NADP as a co-enzyme?

  1. Pyruvate carboxylase

  2. Pyruvate dehydogenase

  3. Glucose 6 phosphate dehydrogenase

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

Glucose 6 phosphate dehydrogenase does not use NADP as its co-enzyme.

Multiple choice

The first stable compound of C4 cycle is

  1. oxaloacetic acid

  2. phospho enol pyruvate

  3. ribulose 1,5-diphosphate(RuDP)

  4. fructose 1,6 diphosphate

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

In C4 plants, phospho enol pyruvate combines with carbon dioxide to form first stable compound oxaloacetic acid.

Multiple choice

Which of the following statements is true about enolpyruvylshikimate phosphate (EPSP) synthase?

  1. It converts phosphoenol pyruvate to pyruvate.

  2. Glyphosate induces EPSP synthase.

  3. Inhibition of EPSP synthase blocks aromatic acid synthesis.

  4. Underproduction of EPSP synthase is helpful in somatic embryogenesis.

  5. EPSP synthase is not required for plant cells.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Glyphosate inhibits EPSP synthase, thereby inhibiting aromatic acid biosynthasis.

Multiple choice

Assertion: The inhibition of glycolysis by oxygen is referred to as Pasteur effect. Reason: This is due to inhibition of the enzyme phosphofructokinase by ATP and citrate.

Directions: In the following question, there are two statements, Assertion (A) and Reason (R). Consider both the statements independently and mark your answer as under:

1. A and R both are correct and R is the correct explanation of A.
2. A and R both are correct and R is not the correct explanation of A.
3. A is correct and R is incorrect.
4. A is incorrect and R is correct.
5. A and R both are incorrect.

  1. A and R both are correct and R is the correct explanation of A.

  2. A and R both are correct and R is not the correct explanation of A.

  3. A is correct and R is incorrect.

  4. A is incorrect and R is correct.

  5. A and R both are incorrect.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The inhibition of glycolysis by oxygen is referred to as Pasteur effect because this is due to inhibition of the enzyme phosphofructokinase by ATP and citrate (formed in the presence of O2).

Multiple choice

The process of gluconeogenesis is absent in brain and muscles because

  1. of the lack of glucose-6-phosphatse

  2. of the storage of creatine phosphate

  3. of the presence of substitutes of glucose

  4. of the high concentration of glucose

  5. muscles and brain do not need gluconeogenesis for their survival
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Glucose-6-phosphatse hydrolyses glucose 6 phosphate into free glucose and phosphate group. This enzyme is absent in brain due to which gluconeogenesis does not occur in brain.

Multiple choice

Formation of glucose from lipids is called _________.

  1. gluconeogenesis

  2. glycognesis

  3. glycogenolysis

  4. lipogenesis

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

It is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as pyruvate, fats, etc.