Biology · Chemistry

Biomolecules and Enzymes

1,501 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

Which of the following is a pair of zinc-containing enzymes?

  1. Carboxypeptidase and ATPase

  2. Carbonic anhydrase and phosphoglucomutase

  3. Carbonic anhydrase and carboxypeptidase

  4. ATPase and phosphoglucomutase

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

This option is correct because carboxypeptidase and carbonic anhydrase are zinc-containing enzymes.

Multiple choice

Match the following Fe containing proteins with the corresponding function and oxidation state of Fe.

   
Fe containing proteins
Function
Oxidation state of Fe
P. Haemoglobin i. Plasma O2 transport a. 2
Q. Myoglobin ii. Muscle O2 storage b. 3
R. Transferrin iii. Plasma Fe transport
S. Catalase iv. H2O2 metabolism

  1. P - ii - a, Q - iv - b, R - i - b, S - iii - b

  2. P - iii - a, Q - iv - a, R - ii - b, S - i - b

  3. P - i - a, Q - ii - a, R - iii - b, S - iv - a

  4. P - ii - b, Q - iii - b, R - iv - a, S - i - a

  5. P - i - b, Q - iii - b, R - ii - a, S - iv - b
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct answer. Haemoglobin is a plasma O2 transport protein. Oxidation number of Fe in haemoglobin is 2. Myoglobin is a muscle O2 storage protein. Oxidation number of Fe in myoglobin is 2. Transferrin is a plasma Fe transport protein. Oxidation number of Fe in transferrin is 3. Catalase is an enzyme, which catalyses H2O2 metabolism. Oxidation number of Fe in catalase is 2.

Multiple choice

Which of the following statements is correct?

  1. Enzymes are nucleic acids.

  2. Repeating units of proteins are peptides.

  3. Saccharides are the most abundant biomolecules on the Earth.

  4. Primary structure of proteins represents linear sequence of amino acids joined together by ester linkage.

  5. Glycogen is a polymer of galactose and glucose.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This option is correct because saccharides (carbohydrates) are the most abundant biomolecules on the Earth.

Multiple choice

Which of the following is a false statement?

  1. Nihydrin test is used for detection of α-amino acids.

  2. Denaturation leads to loss of primary and secondary structure of proteins.

  3. Keratin is an example of fibrous protein.

  4. Albumin is a globular protein.

  5. Isoelectric point is the pH at which no net migration of amino acid occurs under electric field.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct because the denatured protein has the same primary structure as the original. Denaturation leads to loss of secondary, tertiary and quarternary structures of proteins.

Multiple choice

Which of the following are examples of chromoprotein?

  1. Haemoglobin and rhodopsin

  2. Zein and keratin

  3. Haemoglobin and casein

  4. Casein and keratin

  5. Rhodopsin and Zein
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Chromoproteins are proteins, such as hemoglobin or rhodopsin. They contain a pigmented nonprotein group, as heme, riboflavin, or retinal.

Multiple choice

Which of the following is true about proteins?

  1. They exist as heteropolymers

  2. They exist as homopolymers

  3. They exist as monomers

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

Proteins are heteropolymers because they are composed of a sequence of different amino acids linked together, rather than repeating units of the same monomer.