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

The antigen-binding site of an antibody is referred as

  1. conformational epitope

  2. linear epitope

  3. paratope

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

The paratope is the part of an antibody which recognises an antigen, the antigen-binding site of an antibody. It is a small region (of 15-22 amino acids) of the antibody's Fv region and contains parts of the antibody's heavy and light chains.

Multiple choice

Which of the following is an α-amino acid?

  1. Citric acid

  2. Citronella oil

  3. Citronellal

  4. Citrulline
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The organic compound citrulline is an α-amino acid. Although citrulline is not coded for by DNA directly, several proteins are known to contain citrulline as a result of a posttranslational modification.

Multiple choice

Proteins make up about half of the human body's dry weight. Among the following, ------------------------ is a protein.

  1. Collagen

  2. Collodion

  3. Congo red

  4. Coomassie Brilliant Blue
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Collagen is a group of naturally occurring proteins found, in nature, exclusively in animals, especially in the flesh and connective tissues of mammals. It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content.

Multiple choice

Which of the following statements is correct regarding histone proteins?

  1. They are acidic proteins and are present in prokaryotes.

  2. They are basic proteins and are present in prokaryotes.

  3. They are acidic proteins and are present in eukaryotes.

  4. They are basic proteins and are present in eukaryotes.

  5. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Histones are basic proteins and are present in eukaryotes.

Multiple choice

Protein of silk thread is

  1. fibroin

  2. albumin

  3. keratin

  4. globulin

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

The protein fibre of silk is mainly composed of fibroin and is produced by certain insect larvae to form cocoons.

Multiple choice

The protein present in silk thread is

  1. fibroin

  2. keratin

  3. albumin

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

Fibroin is an insoluble protein present in silk created by spiders, the larvae of Bombyx mori etc.

Multiple choice

Which of the following are histones?

  1. Acidic proteins

  2. Basic proteins

  3. Mucoproteins

  4. Glycoproteins

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

Histones are highly alkaline or basic proteins that are found in eukaryotic cell nuclei. 

Multiple choice

Which pair of metalloenzymes does not contain cobalt?

  1. Isobutyryl - CoA mutase

  2. Methylmalonyl - CoA mutase

  3. Methionyl aminopeptidase

  4. Nitrile hydratase

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

Cytochrome oxidase metalloenzyme contains copper. Cytochrome oxidase is a metalloenzyme containing copper and a porphyrin, found in mitochondria and important in cell respiration as an agent of electron transfer from certain cytochrome molecules to oxygen molecules.