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

Identify the incorrectly matched pair.

  1. J. Sumner - Crystallisation of first enzyme

  2. F. A. Lipmang - Discovery of coenzyme-A and its role in metabolism

  3. E. Fischer and Krebs - Alteration of enzyme activity by phosphorylation/ dephosphorylation

  4. F. Sanger - Action of enzymes

  5. W. Arber, D. Nathans and Hamilton O. Smith - Discovery of restriction enzymes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 Otto H. Warnburg gave action of enzymes. The Nobel Prize in Physiology or Medicine 1931 was awarded to Otto Warburg for his discovery of the nature and mode of action of the respiratory enzyme. The Nobel Prize in Chemistry 1958 was awarded to Frederick Sanger for his work on the structure of proteins, especially that of insulin.

Multiple choice

Directions: Read the following information and answer the given question.

Raman had his first day at gym today. He had exercised hard over there for the first time. After reaching home he realised his calves are paining. His mother advised him to take rest and not to get worried as he had got cramps. Raman followed his mother's advice.

Which pathway of respiration is used for breakdown of glucose during strenuous exercise?

  1. Aerobic respiration in mitochondria

  2. Anaerobic respiration

  3. Aerobic respiration in cytoplasm

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

When muscles work hard and oxygen is depleted, the body switches to anaerobic respiration to continue producing energy, resulting in lactic acid buildup.

Multiple choice

Which of the following pairs represents hydrolases only?

  1. Acetate kinase and alanine deaminase

  2. Glucose-phosphate isomerase and alanine racemase

  3. Oxalate decarboxylase and isocitrate lyase

  4. Lipase and sucrase

  5. Cytochrome oxidase and lactate dehydrogenase
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Yes, it is the correst answer.

Multiple choice

Which of the following statements regarding metabolites is INCORRECT?

  1. Alcohol is a primary metabolite.

  2. The metabolome forms a large network of metabolic reactions.

  3. The rate of degradation of a metabolite is an important determinant of the duration and intensity of its action.

  4. Some antibiotics use sceondary metabolites as precursors.

  5. A secondary metabolite has an important ecological function.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Some antibiotics use primary metabolites as precursors.

Multiple choice

Actinomycin is responsible for

  1. reconversion of ADP into ATP

  2. release of Ca ions

  3. muscle contraction

  4. reformation of ATP
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Actinomycin is responsible for muscle contraction.

Multiple choice

The proteins which accelerate metabolic reactions and known as catalytic proteins are:

  1. Enzymes

  2. Conjugated Proteins

  3. Simple Proteins

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

Majority of the proteins are the most variable and highly specialized enzymes. Acting as organic catalysts, they accelerate metabolic reactions. Virtually, every type of metabolic reaction is driven by a particular or specific type of enzyme. Hence, metabolic reactions of thousands of different kinds in every cell require enzymes of thousands of different kinds. In fact, the basis of the phenotypic expression of every hereditary characteristic is a specific type of metabolic reaction which  in turn, is driven by a specific type of enzyme. Synthesis of defective or abnormal enzymatic proteins, therefore, forms the basis of genetic diseases. About 1400 such diseases are known in case of human beings.

Multiple choice

Which of the following statements concerning the excretion of acid by the nephrons are true?

  1. Acid can be excreted as NH3 ions.

  2. Acid excretion mainly occurs in the early nephron.

  3. In the distal nephron, secreted hydrogen ions mainly contribute to bicarbonate reabsorption.

  4. Sodium phosphate is a urinary buffer.

  5. Urine is usually alkaline.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sodium phosphate can exist as Na2HPO4 or NaH2PO4 and the two form a buffer pair. The form NaHPO4 is a weak base which can accept a hydrogen ion to become NaH2PO4. Similarly NaH2PO4 is a weak acid which can donate a hydrogen ion to become Na2HPO4.