In This Post we are  providing Chapter-9 Biomolecules NCERT MCQ for Class 11 Biology which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON BIOMOLECULES

Question 1 : In RNA, thymine is replaced by

• a) Uracil
• b) Guanine
• c) Both
• d) None of these

Answer : Uracil

Question 2:  Carrier ions like Na⁺ facilitate the absorption of substances like:

• a) amino acids and glucose
• b) glucose and fatty acids
• c) fatty acids and glycerol
• d) fructose and some amino acids

Answer : amino acids and glucose

Question 3 : An enzyme brings about

• a) reduction in activation energy
• b) increase in activation energy
• c) increase in reaction time
• d) decrease in reaction time

Answer : reduction in activation energy

Question 4 : The enzymes hexokinase which catalyses glucose to glucose-6-phosphate in glycolysis is inhibited by glucose- 6-phosphate. This is an example of

• a) feedback allosteric inhibition
• b) non-competitive inhibition
• c) competitive inhibition
• d) None of these

Answer : feedback allosteric inhibition

Question 5 : The enormous diversity of protein molecules is due mainly to the diversity of

• a) amino acid sequences within the protein molecule
• b) peptide bonds
• c) R groups on the amino acids
• d) amino groups on the amino acids

Answer : amino acid sequences within the protein molecule

Question 6: Length of one turn of the helix in a B-form DNA is approximately

• a) 3.4 nm
• b) 0.34 nm
• c) Both
• d) None of these

Answer : 3.4 nm

Question 7 : Which of the following sets contains polysaccharides?

• a) Starch, glycogen, cellulose
• b) Sucrose, maltose, cellulose
• c) Galactose, starch, sucrose
• d) Glucose, fructose, lactose

Answer : Starch, glycogen, cellulose

Question 8 : The most basic amino acid is

• a) Arginine
• b) Glycine
• c) Histidine
• d) Glutamine

Answer : Arginine

Question 9 : The helical structure of protein is stabilized by

• a) Hydrogen bonds
• b) Disulphide bonds
• c) Peptide bonds
• d) None of these

Answer : Hydrogen bonds

Question 10: The Km value of the enzyme is the value of the substrate concentration at which the reaction reaches to

• a) ½ Vmax
• b) Zero
• c) ¼ Vmax
• d) 2 Vmax

Answer :  ½ Vmax

Question 11 : Which group contains biocatalysts?

• a) Peptidase, amylase, rennin
• b) Glucose, amino acids, fatty acids
• c) Rhodopsin, pepsin, steapsin
• d) Myosin, oxytocin, adrenalin

Answer : Peptidase, amylase, rennin

Question 12: Enzymes that catalyse removal of groups from substrates by mechanisms other than hydrolysis, and addition of groups to double bonds, are called

• a) lyases
• b) dehydrogenases
• c) Both
• d) None of these

Answer : lyases

Question 13 :  Oils are rich in

• a) Fats that are generally liquid at room temperature
• b) Glycerol that possesses three hydroxyl groups
• c) Esters of fatty acids
• d) Saturated fatty acids

Answer : Fats that are generally liquid at room temperature

Question 14 : Bonds that do not exist in tertiary structure of proteins

• a) Phosphodiester bonds
• b) Hydrophobic etnractions
• c) Ionic bonds
• d) Covalent bonds

Answer : Phosphodiester bonds

Question 15 : Cleavage of specific covalent bonds and removal of groups without hydrolysis is the property of

• a) Lyases
• b) Transferases
• c) Isomerases
• d) Hydrolases

Answer : Lyases