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

Most abundant protein in the world is _________.

  1. albumin

  2. collagen

  3. osteocalcin

  4. RuBisCO

  5. keratin
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

RuBisCO (Ribulose-1, 5-bisphosphate carboxylase) is thought to be the most abundant protein in the world, since it is present in every plant that undergoes photosynthesis and molecular synthesis through Calvin cycle.

Multiple choice

Which of the following is a pair of sulphur containing amino acids?

  1. Leucine and Valine

  2. Cysteine and Methionine

  3. Serine and Threonine

  4. Cysteine and Leucine

  5. Threonine and Methionine
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cysteine is a sulphur containing α-amino acid with the chemical formula HOOCCH(NH2)CH2SH. Methionine is sulphur containing α-amino acid with the chemical formula HOOCCH(NH2)CH2CH2SCH3.

Multiple choice

What is lysine?

  1. Amino acid

  2. Loosely packed chromatin

  3. Densely packed chromatin

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

This option is correct. Lysine is an amino acid.

Multiple choice

The most abundant protein of serum is

  1. gamma globulin

  2. albumin

  3. prothrombin

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

Serum albumin accounts for more than 50 percent of blood protein. It is produced in the liver and transports hormones, fatty acids and bilirubin throughout the body.

Multiple choice

Napins are seed storage proteins, consist of two polypeptide chains. Which of the following plant species contains napin protein?

A. Berssica campestris B. Zea mays C. Degenia velebitica

  1. Only A

  2. Only B

  3. Only C

  4. Only B and C

  5. Only A and C
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Osborne (1924) classified seed storage proteins into groups on the basis of their extraction and solubility in water (albumins), dilute saline (globulins), alcohol-water mixtures (prolamins), and dilute acid or alkali (glutelins). In Crucifereae or Bressicaceae family, the seed storage proteins are called napins. The examples of cruciferae family are- Berssica campestris, Degenia velebitica, Arabis aculeolata, etc. Zea mays belongs to the family Poaceae and contains zein as seed storage proteins.

Multiple choice

In growing children, the conditionally essential amino acids is/are

  1. 2-amino-3-methylbutanoic acid
  2. 2-Amino-3-phenylpropanoic acid
  3. 2-Amino-3-sulphydrylpropanoic acid

  1. Only 1

  2. Only 2

  3. Only 3

  4. Only 1 and 2

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

Six amino acids are considered conditionally essential in the human diet, meaning their synthesis can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress. These six are 2-Amino-3-sulphydrylpropanoic acid, 2-Amino-5-guanidinopentanoic acid, Aminoacetic acid, 2-Amino-4-carbamoylbutanoic acid, Pyrrolidine-2-carboxylic acid and L-2-Amino-3-(4-hydroxyphenyl) propanoic acid.

Multiple choice

Which of the followings indispensable amino acids are essential for human?

A. Pyrrolidine-2-carboxylic acid B. 4-hydroxyphenylalanine C. 2-Amino-4-methylpentanoic acid D. 2,6-Diammoniohexanoic acid

  1. Only A and B

  2. Only B and C

  3. Only C and D

  4. Only B, C and D

  5. All of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The indispensable amino acids are those amino acids that cannot be synthesised by the organism being considered and therefore must be supplied in its diet. The amino acids regarded as essential for humans are 2-Amino-4-methylpentanoic acid, 2,6-Diammoniohexanoic acid, etc. Hence, C and D both are indispensable amino acids and others are conditionally amino acids.