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

The optically inactive amino acid is

  1. serine

  2. glycine

  3. leucine

  4. all of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Glycine, or aminoethanoic acid (NH2CH2COOH) is the only amino acid that is not optically active as it does not contain a chiral carbon.

Multiple choice

Denaturation of proteins involves breakdown of

  1. primary structure only

  2. secondary structure only

  3. primary, secondary and tertiary structures

  4. secondary, tertiary and quaternary structures
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Denaturation of proteins involves the disruption and possible destruction of secondary, tertiary and quaternary structures.

Multiple choice

Which of the following statements is correct?

  1. Vitamin D is a water soluble vitamin.

  2. RNA does not contain uracil.

  3. Isoelectric pH is that pH at which protein is electrically neutral.

  4. Glycine is an example of chiral amino acid.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, pH at which protein is electrically neutral is called as isoelectric pH.

Multiple choice

A ……………….. is the non-protein chemical compound that is required for the activity of an enzyme.

  1. <span style="font-size:10.0pt;font-family:"Arial","sans-serif";mso-fareast-font-family:"Times" new="lang=EN-GB">co-factor

  2. <span style="font-size:10.0pt;font-family:Arial,sans-serif;mso-fareast-font-family:Times" new="lang=EN-GB">co-enzyme

  3. <span style="font-size:">prosthetic group

  4. <span style="font-size:">activator
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A co-factor is the non-protein chemical compound that is bound to a protein and is required for the protein's biological activity. These proteins are commonly enzymes, and co-factors can be considered helper molecules that assist in biochemical transformations.

Multiple choice

Match the following:

 
Names of proteins Functions
a. Fibrinogens 1. They help in maintaining the osmotic balance.
b. Globulins 2. They are primarily involved in defence mechanisms of the body.
c. Albumins 3. They are needed for coagulation of blood.

  1. a - 3, b - 2, c - 1

  2. a - 3, b - 1, c - 2

  3. a - 1, b - 3, c - 2

  4. a - 2, b - 3, c - 1

  5. a - 1, b - 2, c - 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option. Fibrinogens are needed for coagulation of blood. Globulins are primarily involved in defence mechanisms of the body. Albumins help in maintaining the osmotic balance.

Multiple choice

Which amino acid is achiral?

  1. Glycine

  2. Proline

  3. Alanine

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

Glycine derived from glyceraldehyde has no optical activity as it is not chiral (achiral).

Multiple choice

Ceruloplasmin is a type of

  1. glycoproteins

  2. phosphoproteins

  3. metalloprotein

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

Ceruloplasmin is a blue copper protein (Metalloprotein) found in the alpha 2-globulin fraction of vertebrate plasma. It is a single-chain glycoprotein of molecular weight 132 000. It contains six copper atoms per molecule, comprising three or possibly four different types of copper.

Multiple choice

2 ribosomal sub-units remain together with each other because of____________. -

  1. high concentration of Mg++ ions

  2. low concentration of Mn++ ions

  3. high concentration of Ca++ ions

  4. low concentration of Mg++ ions
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ribosome is large & complicated cell organelle presents in almost all living cell that serevs as the major site of biological protein synthesis. 2 ribosomal sub-units remain together with each other because of high concentration of Mg++ ions.

Multiple choice

Which of following are essential properties of prokaryotes (methanogenic bacteria)?

  1. These cannot develop automatically.
  2. Those dwelling in mud supernatant may need organic development factors for development.
  3. These cannot transform hydrogen to methane.
  4. These cannot utilize CO2 as growth substrate in which CO2 is reduced to methane.

Choose the right answer using the options provided below:

  1. 1, 2 and 3

  2. 1, 3 and 4

  3. 1, 2 and 4

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

Essential properties of prokaryotes (methanogenic bacteria): Those dwelling in mud supernatant may need organic development factors for development. These cannot transform hydrogen to methane & cannot utilize CO2 as growth substrate in which CO2 is reduced to methane.