CBSE Class 11 Biology Biomolecules MCQs Set 05

Question: Inulin is a polymer of
a) Glucose
b) Galactose
c) Fructose
d) Arabinose
Answer: c

Question: Most abundant protein in human body is
a) Myosin
b) Albumin
c) Actin
d) Collagen
Answer: d

Question: The bond between phosphate and hydroxyl group of sugar in nucleic acid is
a) Peptide bond
b) Glycosidic bond
c) Ester bond
d) None of these
Answer: c

Question: The Km value of an enzyme is the substrate concentration at which the reaction reaches
a) Zero
b) 2 Vmax
c) ½ Vmax
d) ¼ Vmax
Answer: c

Question: Feedback inhibition of enzymes is affected by
a) Intermediate end products
b) Enzyme
c) Substrate
d) End product
Answer: d

Question: Which of the following is correct regarding enzymes?
a) Holoenzyme = Apoenzyme + Coenzyme
b) Coenzyme = Apoenzyme + Holoenzyme
c) Holoenzyme = Coenzyme + Co-factor
d) Apoenzyme = Holoenzyme + Coenzyme
Answer: a

Statement Type Questions

Question: Which statement is incorrect about coenzyme?
a) Every coenzyme is a cofactor and every cofactor is a coenzyme.
b) Every coenzyme is a cofactor and every cofactor is not a coenzyme.
c) Most of the coenzymes are nucleotides and are composed of vitamins.
d) Coenzymes are the active constituents of enzyme.
Answer: a

Question: Which of the following statements are correct?
(i) Chitin, a complex or heteropolysaccharide occurring in exoskeleton, consists of NAG.
(ii) Glucosamine and N-acetyl glucosamine are modified sugars.
(iii) Cellulose shows blue colour when treated with I₂.
(iv) Starch in plants and glycogen in animals are store houses of energy.
(v) Right end of polysaccharide is reducing end while left end is non-reducing end.
a) (i), (ii) and (iii)
b) (iii), (iv) and (v)
c) All except (iii)
d) All except (v)
Answer: c

Question: The steps in catalytic cycle of enzyme action are given in random order. The correct order is:
(i) The enzyme releases the products; enzyme is free to bind another substrate.
(ii) Active site in close proximity breaks the bond of substrate and forms E-P complex.
(iii) Binding of substrate induces the enzyme to alter shape for tighter fit.
(iv) Substrate binds to active site of enzyme.
a) (i), (ii), (iii), (iv)
b) (iv), (iii), (ii), (i)
c) (i), (iii), (ii), (iv)
d) (i), (ii), (iv), (iii)
Answer: b

Question: Which option is correct for the following statements?
(i) The metabolic pathway converting acetic acid to cholesterol is endothermic.
(ii) Anabolic pathway is endergonic; catabolic pathway is exergonic.
(iii) Without metabolism there cannot be a living state.
a) All are correct
b) All are wrong
c) (i) and (ii) are correct
d) Only (iii) is correct
Answer: a

Assertion/Reason Type Questions

In the following questions, a statement of Assertion is followed by a statement of Reason.
(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
(b) If both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion.
(c) If Assertion is true but Reason is false.
(d) If both Assertion and Reason are false.

Question: Assertion: Glycosidic bonds are formed by dehydration.
Reason: In polysaccharides, individual monosaccharide is linked by glycosidic bond.
Answer: b

Question: Assertion : Unsaturated fats are more reactive compared with the saturated fats.
Reason : Unsaturated fats have only single bonds in their structure.
Answer: c

Question: Assertion: The amino acid glycine comes under the category of nonessential amino acids.
Reason: This is due to the fact that it can not be synthesised in the body.
Answer: c

Matching Type Questions

Question: Which one of the following is wrongly matched?
(a) Fungi – Chitin
(b) Phospholipid – Plasma membrane
(c) Enzyme – Lipopolysaccharide
(d) ATP – Nucleotide derivative
Answer: c

Question: Choose the mismatch pair
(a) Glutamic acid – Acidic
(b) Lysine – Basic
(c) Valine – Charged
(d) Phenylalanine – Aromatic
Answer: c

Question: Which of the following is wrongly matched ?
(a) Ribozyme – Proteinaceous in nature.
(b) Apoenzyme – The protein part of enzyme.
(c) Co-enzyme – Loosely attached organic cofactor of haloenzyme
(d) Co-factors – Non-protein part of haloenzyme.
Answer: a

Critical Thinking Type Questions

Question: When triglycerides are solid at ordinary room temperature, they are called
a) Oils
b) Gases
c) Fats
d) None of these
Answer: c

Question: The information in a genetic nucleic acid resides in the
a) Number of nucleotides
b) Kinds of nucleotides
c) Sequence of nucleotides
d) All of the above
Answer: c

Question: The quaternary structure of human haemoglobin is best described as a
a) Dimer of identical subunits
b) Dimer of different subunits
c) Tetramer of four different subunits
d) Tetramer of two different subunits
Answer: d

Question: Sugar–phosphate backbone in nucleic acid
a) Is hydrophilic in nature
b) Is negatively charged
c) Shows polarity
d) All of the above
Answer: d

Question: Primary or secondary structure of polypeptide is stabilized mainly by
a) Disulphide bonds
b) Ionic bonds
c) Hydrogen bonds
d) Hydrophobic interactions
Answer: c

Question: A nucleoside differs from a nucleotide by not having
a) Sugar
b) Nitrogen
c) Phosphate
d) Phosphate and sugar
Answer: c

Question: Enzymes that break nucleic acids into nucleotides belong to which class?
a) Oxidoreductases
b) Transferases
c) Hydrolases
d) Lyases
Answer: c

Question: What happens when the cofactor is removed from an enzyme?
a) Catalytic activity is lost
b) Enzyme becomes temporarily inactive
c) Substrate molecules do not closely relate to enzyme
d) Both b and c
Answer: a

Question: Why does the velocity of an enzymatic reaction not increase beyond a certain substrate concentration?
a) Enzyme molecules become equal to substrate molecules
b) Enzyme molecules are fewer than substrate molecules
c) Substrate molecules do not closely resemble enzyme molecules
d) Both b and c
Answer: a