Biology · Chemistry

Biomolecules and Enzymes

1,432 Questions

This topic focuses on biomolecules, specifically proteins, enzymes, and amino acids. It includes questions on enzyme structures, protein folding, and catalysis. These concepts are crucial for medical and biology competitive exams.

Enzyme catalysisProtein structuresAmino acid synthesisPolypeptide chainsBiomolecule properties

Biomolecules and Enzymes Questions

Multiple choice

Trypsin is an enzyme which changes

  1. Starch to maltose

  2. Proteins to peptones

  3. Peptones to peptide

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

Trypsin is an enzyme which changes peptones to peptide.

Multiple choice

Which of the following bacteria gives Cry proteins?

  1. E. coli

  2. Bacillus anthracis

  3. Yersinia pestis

  4. Pseudomonas

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

Bacillus thuringiensis (Bt) is a spore forming bacterium that produces crystal proteins (Cry proteins), which are toxic to many species of insects.

Multiple choice

Which of the following is a selenium containing enzyme?

  1. Glutathione peroxidase

  2. Carbonic anhydrase

  3. Urease

  4. Dopamine beta-hydroxylase

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

Selenium is an important constituent of the enzyme glutathione peroxidase, which is responsible for destroying lipid-damaging peroxides.

Multiple choice

Which of the following matches of metalloenzyme and metal cofactors are incorrect? P. Tyrosinase : Copper Q. Urease : Copper R. Dopamine β-hydroxylase : Nickel S. Catechol dioxygenase : Iron

  1. Only P and Q

  2. Only P and S

  3. Only Q and R

  4. Only Q and S

  5. Only R and S
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Urease is a nickel containing metalloenzyme of high molecular weight that catalyses the hydrolysis of urea into carbon dioxide and ammonia. Dopamine β-hydroxylase is a copper containing enzyme that synthesises norepinephrine from dopamine.

Multiple choice

Which of the following are examples of iron-sulphur proteins?

  1. Rubredoxin
  2. Methane monooxygenase
  3. Rieske proteins
  4. Aconitase

  1. 1 and 2 only

  2. 1, 2 and 3 only

  3. 1, 3 and 4 only

  4. 2 and 3 only

  5. 2, 3 and 4 only
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Rubredoxin is a small iron-sulphur protein found in various sulphur-metabolising bacteria. Rieske proteins are iron-sulphur protein components of cytochrome bc1 complexes and cytochrome b6f complexes, which were first discovered and isolated by John S. Rieske and co-workers in 1964. Aconitase is an iron-sulphur protein that catalyses the interconversion of citrate and isocitrate.