CBSE Class 12 Chemistry Biomolecules Question Bank Set B

Question. Which is not true statement?
(a) a-Carbon of a-amino acid is asymmetric.
(b) All proteins are found in L-form.
(c) Human body can synthesise all proteins they need.
(d) At pH = 7 both amino and carboxylic groups exist in ionised form. 
Answer. B

Question. Which is the correct statement?
(a) Starch is a polymer of a-glucose.
(b) Amylose is a component of cellulose.
(c) Proteins are composed of only one type of amino acid.
(d) In cyclic structure of fructose, there are four carbons and one oxygen atom. 
Answer. A

Question. Haemoglobin is
(a) a vitamin
(b) a carbohydrate
(c) an enzyme
(d) a globular protein.
Answer. D

Question. The secondary structure of a protein refers to
(a) regular folding patterns of continuous portions of the polypeptide chain
(b) three-dimensional structure, specially the bond between amino acid residues that are distant from each other in the polypeptide chain
(c) mainly denatured proteins and structures of prosthetic groups
(d) linear sequence of amino acid residues in the polypeptide chain.
Answer. A

Question. Enzymes are made up of
(a) edible proteins
(b) proteins with specific structure
(c) nitrogen containing carbohydrates
(d) carbohydrates. 
Answer. B

Question. Which of the following is correct?
(a) Cycloheptane is an aromatic compound.
(b) Diastase is an enzyme.
(c) Acetophenone is an ether.
(d) All of these.
Answer. B

Question. The function of enzymes in the living system is to
(a) catalyse biochemical reactions
(b) provide energy
(c) transport oxygen
(d) provide immunity.
Answer. A

Question. Which of the following statements about enzymes is true?
(a) Enzymes catalyse chemical reactions by increasing the activation energy.
(b) Enzymes are highly specific both in binding chiral substrates and in catalysing their reactions.
(c) Enzymes lack in nucleophilic groups.
(d) Pepsin is proteolytic enzyme.
Answer. B

Question. Enzymes take part in a reaction and
(a) decrease the rate of a chemical reaction
(b) increase the rate of a chemical reaction
(c) both (a) and (b)
(d) none of these. 
Answer. B

Question. Deficiency of vitamin B1 causes the disease
(a) convulsions
(b) beri-beri
(c) cheilosis
(d) sterility. 
Answer. B

Question. Which of the following is not a fat soluble vitamin?
(a) Vitamin B complex
(b) Vitamin D
(c) Vitamin E
(d) Vitamin A 
Answer. A

Question. Which of the following vitamins is water soluble?
(a) Vitamin E
(b) Vitamin K
(c) Vitamin A
(d) Vitamin B 
Answer. D

Question. The human body does not produce
(a) enzymes
(b) DNA
(c) vitamins
(d) hormones. 
Answer. C

Question. Vitamin B12 contains
(a) Fe (II)
(b) Co (III)
(c) Zn (II)
(d) Ca (II) 
Answer. B

Question. The central dogma of molecular genetics states that the genetic information flows from
(a) Amino acids → Proteins → DNA
(b) DNA → Carbohydrates → Proteins
(c) DNA → RNA → Proteins
(d) DNA → RNA → Carbohydrates
Answer. C

Question. The correct statement regarding RNA and DNA, respectively is
(a) the sugar component in RNA is a arabinose and the sugar component in DNA is ribose
(b) the sugar component in RNA is 2′-deoxyribose and the sugar component in DNA is arabinose
(c) the sugar component in RNA is arabinose and the sugar component in DNA is 2′-deoxyribose
(d) the sugar component in RNA is ribose and the sugar component in DNA is 2′-deoxyribose.
Answer. D

Question. In DNA, the linkages between different nitrogenous bases are
(a) phosphate linkage
(b) H-bonding
(c) glycosidic linkage
(d) peptide linkage. 
Answer. B

Question. The segment of DNA which acts as the instrumental manual for the synthesis of the protein is
(a) ribose
(b) gene
(c) nucleoside
(d) nucleotide. 
Answer. B

Question. In DNA, the complimentary bases are
(a) adenine and guanine; thymine and cytosine
(b) uracil and adenine; cytosine and guanine
(c) adenine and thymine; guanine and cytosine
(d) adenine and thymine; guanine and uracil.
Answer. C

Question. RNA and DNA are chiral molecules, their chirality is due to
(a) chiral bases
(b) chiral phosphate ester units
(c) D-sugar component
(d) L-sugar component. 
Answer. C

Question. A sequence of how many nucleotides in messenger RNA makes a codon for an amino acid?
(a) Three
(b) Four
(c) One
(d) Two 
Answer. A

Question. Chargaff’s rule states that in an organism
(a) amount of adenine (A) is equal to that of thymine (T) and the amount of guanine (G) is equal to that of cytosine (C)
(b) amount of adenine (A) is equal to that of guanine (G) and the amount of thymine (T) is equal to that of cytosine (C)
(c) amount of adenine (A) is equal to that of cytosine (C) and the amount of thymine (T) is equal to that of guanine (G)
(d) amounts of all bases are equal. 
Answer. A

Question. Which of the following is correct about H-bonding in nucleotide?
(a) A – T, G – C
(b) A – G , T – C
(c) G – T, A – C
(d) A – A, T – T
Answer. A

Question. An example of biopolymer is
(a) teflon
(b) neoprene
(c) nylon-6, 6
(d) DNA. 
Answer. D

Question. The couplings between base units of DNA is through
(a) hydrogen bonding
(b) electrostatic bonding
(c) covalent bonding
(d) van der Waals’ forces.
Answer. A

Question. Which of the following statements is not correct?
(a) Ovalbumin is a simple food reserve in eggwhite.
(b) Blood proteins thrombin and fibrinogen are involved in blood clotting.
(c) Denaturation makes the proteins more active.
(d) Insulin maintains sugar level in the blood of a human body. 
Answer. C

Question. Which of the following hormones is produced under the conditions of stress which stimulate glycogenolysis in the liver of human beings?
(a) Thyroxin
(b) Insulin
(c) Adrenaline
(d) Estradiol 
Answer. C

Question. Which of the following hormones contains iodine?
(a) Testosterone
(b) Adrenaline
(c) Thyroxine
(d) Insulin 
Answer. C

Question. Which of the following is an amine hormone?
(a) Insulin
(b) Progesterone
(c) Thyroxine
(d) Oxypurin 
Answer. C

Question. Which one of the following is a peptide hormone?
(a) Adrenaline
(b) Glucagon
(c) Testosterone
(d) Thyroxine 
Answer. B

Question. The hormone that helps in the conversion of glucose to glycogen is
(a) cortisone
(b) bile acids
(c) adrenaline
(d) insulin. 
Answer. D

Question. Which one is responsible for production of energy in biochemical reaction?
(a) Thyroxine
(b) Adrenaline
(c) Oestrogen
(d) Progesterone 
Answer. A

Question. The cell membranes are mainly composed of
(a) fats
(b) proteins
(c) phospholipids
(d) carbohydrates. 
Answer. C

Question. Phospholipids are esters of glycerol with
(a) three carboxylic acid residues
(b) two carboxylic acid residues and one phosphate group
(c) one carboxylic acid residue and two phosphate groups
(d) three phosphate groups. 
Answer. B

Question. The number of molecules of ATP produced in the lipid metabolism of a molecule of palmitic acid is
(a) 56
(b) 36
(c) 130
(d) 86
Answer. C

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