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 evs - i constituents of food dietary sources of proteins types of nutrients calorific value of nutrients

Identify the incorrect match between the protein and its role.

  1. Keratin structural component of hair

  2. Immunoglobulins protection of body against diseases
  3. Haemoglobin transport of $O _2$ in muscles

  4. Thrombin blood clotting
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The pigmented proteins in the muscle fibers which impart the red color to the muscles is called myoglobin. This protein is involved in the process of oxygen storage in the muscle tissues by binding to it. In conditions such as hypoxia oxygen is released by the myoglobin. Hence it is the oxygen trasnsporter to the muscle fibers. Thus the correct answer is option C. 
Multiple choice evs - i constituents of food dietary sources of proteins types of nutrients calorific value of nutrients


The following is a storage protein

  1. Keratin

  2. Collagen

  3. Glutelin

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

A) Keratin is the protein that is the structural material making up hair, horns, claws, hooves and the outer layer of human skin.

B) Collagen is the building block of the entire body, from the skin to the gut.
C) Glutelin is the storage protein that is found in the species of grass family commonly known as gluten.
D) Haemoglobin is a blood protein that helps in the transport of oxygen.
Hence, the correct answer is 'Glutelin'.

Multiple choice evs - i constituents of food dietary sources of proteins types of nutrients calorific value of nutrients

The ratio of $H _1$ and $H _3$ proteins in chromatin is?

  1. $1:2$
  2. $2:1$
  3. $1:1$
  4. $1:4$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Histones are a family of basic proteins that associate with DNA in the nucleus and help condense it into chromatin, they are alkaline (basic pH) proteins, and their positive charges allow them to associate with DNA.
  • Five types of histones have been identified: H1 (or H5), H2A, H2B, H3 and H4.
  • The core histones are H2A, H2B, H3, and H4, and the linker histones are H1 and H5. These types of histones are smaller, each consisting of 100-150 residues.
  • H1 and its homologous protein H5 are involved in higher-order structures of chromatin consisting about 220 residues.
  • The ratio of H1 and H3 proteins in chromatin is 1:2
So, the correct option is '1:2'

Multiple choice chemistry measurement and data processing and analysis spectroscopic identification of organic compounds materials science introduction superconducting metals and x-ray crystallography

Which organic macromolecule is responsible for genetic information?

  1. Nucleic Acid

  2. Protein

  3. Nucleus

  4. Lipid

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

Nucleic acid are the organic molecules responsible for genetic information.
Organic Macro-molecules: Organic compounds are those that contain carbon (e.g. carbohydrates, lipids, proteins, nucleic acids).

Multiple choice drug-target interaction pharmaceutical products and drug action medicinal chemistry chemistry in everyday life chemistry body defense system

Which of the following statements is not true about enzyme inhibitors?

  1. Inhibit the catalytic activity of the enzyme.

  2. Prevent the binding of substrate.

  3. Generally a strong covalent bond is formed between an inhibitor and an enzymes.

  4. Inhibitors can be competitive or non-competitive.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Generally a weak bond such as H-bonding, van der Waals interaction etc. is formed between an inhibitor and an enzyme.

Multiple choice drug-target interaction pharmaceutical products and drug action medicinal chemistry chemistry in everyday life chemistry body defense system

Which of the following statements is not true about enzyme inhibitors?

  1. Inhibit the catalytic activity of the enzyme.

  2. Prevent the binding of substrate.

  3. Generally, a strong covalent bond is formed between an inhibitor and an enzyme.

  4. Inhibitors can be competitive or non-competitive.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Enzyme inhibitors bind reversibly and irreversibly.
They bind reversibly with non-covalent bond, whereas, they bind irreversibly with covalent bond where they change the key amino acid residues needed for enzymatic activity.
Hence, option C is correct.
Multiple choice drug-target interaction pharmaceutical products and drug action medicinal chemistry chemistry in everyday life chemistry body defense system

Which site of an enzyme is called allosteric site?

  1. which binds to the cell wall

  2. where drugs bind to an enzyme

  3. which is not the active site, where some drugs bind to an enzyme

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 The allosteric site is the site, which is not the active site, where some drugs bind to an enzyme. Due to this, the shape of the enzyme changes, it becomes difficult for the substrate to recognize the active site of the enzyme. This represents non-competitive inhibition.

Multiple choice drug-target interaction pharmaceutical products and drug action medicinal chemistry chemistry in everyday life chemistry body defense system

The bond formed between an enzyme and an inhibitor:

  1. can be broken easily

  2. cannot be broken easily

  3. is a weak bond

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
If the bond formed between an enzyme and an inhibitor is a strong covalent bond, it cannot be broken easily. Then the enzyme is blocked permanently and the body degrades the enzyme-inhibitor complex and synthesizes the new enzyme.
Multiple choice evs - i constituents of food simple test for nutrients test for nutrients protein and its function nutrients and foodstuffs

Which of the following is made up of amino acids?

  1. Amylase

  2. Glycogen

  3. Phospholipid

  4. Polysaccharide

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

Amylase is a protein enzyme, a polymer of amino acids. Glycogen is homopolysaccharide of D-glucose with highly branched structure (every 8-12 residues as compared to presence of branches in starch for every 24-30 residues). Phopholipids have phosphate and lipids (carbon and hydrogen atoms) while polysaccharides are polymer of simple sugars. RNA is polymer of ribonucleotides. 

Therefore, the correct answer is option A.

Multiple choice evs - i constituents of food simple test for nutrients test for nutrients protein and its function nutrients and foodstuffs

The different amino acids are joined together by peptide bonds to form

  1. Lipids

  2. Proteins

  3. Carbohydrates

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

Proteins are the building blocks, which takes part in several metabolic reaction. They have four different levels of structure primary, secondary, tertiary and quaternary. There are 20 different standard L-α-amino acids used by cells for protein construction. Amino acids contain both a basic amino group and an acidic carboxyl group. This difunctionality allows the individual amino acids to join together in long chains by forming peptide bonds: amide bonds between the -NH2 of one amino acid and the -COOH of another. Sequences with fewer than 50 amino acids are generally referred to as peptides, while the terms protein or polypeptide are used for longer sequences. A protein can be made up of one or more polypeptide molecules. The end of the peptide or protein sequence with a free carboxyl group is called the carboxy-terminus or C-terminus. The terms amino-terminus or N-terminus describe the end of the sequence with a free α-amino group. The amino acids differ in structure by the substituent on their side chains. These side chains confer different chemical, physical and structural properties to the final peptide or protein.
So, the correct answer is option B.

Multiple choice evs - i constituents of food simple test for nutrients test for nutrients protein and its function nutrients and foodstuffs

Choose the correct answer from the alternatives given:
Amino acids are building blocks of

  1. Carbohydrates

  2. Nucleic acids

  3. Lipids

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

Amino acids are the building blocks of polypeptide chain or proteins. These are encoded by the triplet codons of mRNA. Each codon synthesizes a specific amino acid. Example: AUG for methionine, UUU for phenylalanine and so on. Amino acids are connected via the peptide bonds to form the proteins.

Hence, the correct answer is 'Proteins'