Biology

Cellular Respiration and Enzymes

1,551 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

Bacterial enzyme combines O2 with H+ to remove O2 by forming H2O and turns the petri dish into a mini-anaerobic chamber, in a growth culture media. This method is

  1. peroxidase

  2. catalase

  3. oxyrase

  4. superoxide dismutase

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

Oxyrase is a bacterial respiratory enzyme that can be put in media; it combines O2 with H+ to remove O2 by forming H2O and turns the petri dish into a mini-anaerobic chamber. Anaerobic chambers with air locks are filled with inert gas.

Multiple choice

What is the correct elaborated form of NADP?

  1. Nicotinal adenine dinucleotide phosphate

  2. Nicotinamide adrenaline dinucleotide phosphate

  3. Nicotinamide adenine dinucleotide phosphate

  4. Nicotine adrenal dinucleotide phosphate

  5. Nicotinamide adenine dinuclear phosphatide
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

NADP stands for nicotinamide adenine dinucleotide phosphate. It is produced by light-dependent reactions in photosynthesis.

Multiple choice

Which of the following reactions is/are not anabolic?

(a) Glucose + Glucose = Glycogen (b) Glycerol + Fatty acid = Tryglyceride (c) Glucose + Oxygen = CO2 + Water + Energy (d) Amino acid + Amino acid = Protein

  1. only a

  2. a and b

  3. only c

  4. b and c

  5. a and d
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, it is the correct answer as the reaction is not an anabolic reaction. The process in which breaking up of a substance takes place is not anabolic reaction, but a catabolic reaction. Cellular respiration helps cells break sugar, which helps in producing energy.

Multiple choice

At high temperatures, enzymes are

  1. denatured

  2. unaffected

  3. inactivated

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Enzymes are proteins, and high temperatures cause them to lose their specific three-dimensional shape, a process known as denaturation, which renders them non-functional.

Multiple choice

Which of the following enzymes belongs to the category of enzymes that act on the aldehyde or oxo group of donors?

  1. Pyruvate dehydrogenase

  2. Alcohol dehydrogenase

  3. NADH dehydrogenase

  4. Malate dehydrogenase

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

Pyruvate dehydrogenase belongs to Category EC 1.2 of oxidoreductases (EC 1), act on the aldehyde or oxo group of donors. Pyruvate dehydrogenase performs the first two reactions within the pyruvate dehydrogenase complex: decarboxylation of pyruvate and reductive acetylation of lipoic acid.

Multiple choice

In which of the following steps of glycolysis, there is neither expenditure of energy nor formation of ATP?

  1. Phosphorylation of glucose to form glucose 6-phosphate.

  2. Conversion of fructose 6-phosphate to fructose 1,6 diphosphate.

  3. Splitting of fructose 1,6 diphosphate into two molecules of triose phosphates.

  4. Conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate.

  5. Conversion of phosphoenol pyruvate to pyruvate.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Splitting of fructose 1,6 diphosphate into two molecules of triose phosphates, an aldotriose-glyceraldehyde 3-phosphate and one ketotriose - dihydroxy acetone phosphate is catalysed by the enzyme aldolase. There is neither expenditure of energy nor formation of ATP.

Multiple choice

The number of carbon dioxide molecules produced by the oxidation of one molecule of glucose during aerobic respiration is

  1. 2

  2. 4

  3. 6

  4. 8

  5. 10
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

During aerobic respiration, each carbon atoms in a glucose molecule is completely oxidized. Each oxidized carbon is released, along with two oxygen atoms, forming a molecule of carbon dioxide. Glucose contains 6 carbon atoms, thus the number of carbon dioxide molecules produced by the oxidation of one molecule of glucose during aerobic respiration is 6.

Multiple choice

Which of the following statements is/are false regarding glycolysis?

  1. Glycolysis occurs in the cytoplasm of the cell.
  2. All the steps in glycolysis are reversible.
  3. Pyruvate is the end product of glycolysis.

Select the correct answer using codes given below

  1. 1 only

  2. 2 only

  3. 3 only

  4. 1 and 2

  5. 1, 2 and 3
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Three reactions of glycolysis have such a large negative ∆G in the forward direction that they are essentially irreversible.

Multiple choice

Match the entries in column I (enzymes) with that in column II (reactions catalysed by them during glycolysis) and select the correct answer.

 
Column - I
Column - II
P. Glucokinase 1. Conversion of glucose 6-phosphate to fructose 6-phosphate
Q. Phosphogluco isomerase 2. Phosphorylation of fructose 6-phosphate to produce fructose-1,6-diphosphate
R. Phosphofructokinase 3. Phosphorylation of glucose is to form glucose 6-phosphate

  1. P - 1, Q - 2, R - 3

  2. P - 3, Q -1, R - 2

  3. P - 2, Q -1, R - 3

  4. P - 2, Q - 3, R - 1

  5. P - 1, Q - 3, R - 2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Glucose is phosphorylated to form glucose 6-phosphate by the enzyme glucokinase. Glucose 6-phosphate is converted to fructose 6-phosphate by the enzyme phosphogluco isomerise. Fructose 6-phosphate is phosphorylated irreversibly at 1 position catalyzed by the enzyme phosphofructokinase to produce fructose-1,6-diphosphate.

Multiple choice

Which of the following is not true about the chemisosmotic model?

  1. It was given by Peter Mitchell.

  2. The link between proton and ATP formation is an electrochemical potential across the membrane.

  3. It provides a very plausible explanation for the coupled ATP generation.

  4. The unidirectional pumping of protons accounts for the gradient and the capability of the gradient to drive ATP synthesis.

  5. F0F1 forms the ATP synthase complex.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The link between electron and ATP formation is an electrochemical potential across the membrane.