MCQ Chapter 14 Biomolecules Class 12 Chemistry

Please refer to Biomolecules MCQ Questions Class 12 Chemistry below. These MCQ questions for Class 12 Chemistry with answers have been designed as per the latest NCERT, CBSE books and syllabus issued for the current academic year. These objective questions for Biomolecules will help you to prepare for the exams and get more marks.

Biomolecules MCQ Questions Class 12 Chemistry

Please see solved MCQ Questions for Biomolecules in Class 12 Chemistry. All questions and answers have been prepared by expert faculty of standard 12 based on latest examination guidelines.

Question. The total number of basic groups in the following form of lysine is

(a) 1
(b) 2
(c) 3
(d) 4     

Question. Biuret test is not given by
(a) carbohydrates
(c) urea
(b) polypeptides
(d) proteins       

Question. The substituents R₁ and R₂ for nine peptides are listed in the table given below. How many of these peptides are positively charged at pH = 7.0?

(a) 2
(b) 4
(c) 6
(d) 8     

Question. Which of the following is a heterocyclic amino acid?
(a) Glycine
(b) Alanine
(c) Phenylalanine
(d) Tryptophan     

Question. A compound with molecular mass 180 is acylated with CH₃COCI to get a compound with molecular mass 390. The number of amino groups present per molecule of the former compound is 
(a) 2
(b) 5
(c) 4
(d) 6     

Question. Which of the following set consists only of essential amino acids?
(a) Alanine, tyrosine, cystine
(b) Leucine, lysine, tryptophane
(c) Alanine, glutamine, lycine
(d) Leucine, proline, glycine       

Question. Which one of the following is not a protein? 
(a) Wool
(b) Nail
(c) Hair
(d) DNA     

Question. α-helix is found in
(a) DNA
(b) RNA
(c) lipid
(d) carbohydrates
(e) protein   

Question. Which one of the following does not correctly match with each other?
(a) Silk-polyamide
(b) Lipase-enzyme
(c) Butter-fat
(d) Oxytocin-enzyme     

Question. The number of disulphide linkages present in insulin are
(a) 1
(b) 2
(c) 3
(d) 4   

Question. A decapeptide (mol. wt. 796) on complete hydrolysis gives glycine (mol. wt. 75), alanine and phenylalanine. Glycine contributes 47% to the total weight of the hydrolysed products. The number of glycine units present in the decapeptide is
(a) 3
(b) 4
(c) 5
(d) 6     

Question. A Zwitter ion is 
(a) negatively charged ion without metal atom
(b) a heavy ion with a small charge on it
(c) an ion with positive and negative charge at different points on it
(d) a positively charged ion without a metal atom       

Question. Which of the following is a simplest amino acids?
(a) Glycine
(b) Alanine
(c) Leucine
(d) Valine     

Question. Which of the following element is present in haemoglobin?
(a) Na
(b) Ca 
(c) Fe
(d) Au     

Question. The number of amino acids and number of peptide bonds in a linear tetrapeptide (made of different amino acids, are respectively 
(a) 4 and 4
(b) 5 and 5
(c) 5 and 4
(d) 4 and 3 

Question. Which of the following describes the overall three dimensional folding of a polypeptide? 
(a) Primary structure
(b) Secondary structure
(c) Tertiary structure
(d) Quaternary structure   

Question. Which of the following compound shows aromatic properties?
(a) Valine
(c) Serine
(b) Leucine
(d) Tyrosine     

Question. A tetrapeptide has – COOH group on alanine. This produces glycine (Gly), valine (Val), phenyl alanine (Phe) and alanine (Ala), on complete hydrolysis. For this tetrapeptide, the number of possible sequences (primary structures) with — NH₂ group attached to a chiral centre is
(a) 7
(b) 5
(c) 4
(d) 8     

Question. Which one of the following statements is correct? 
(a) All amino acids except lysine are optically active
(b) All amino acids are optically active
(c) All amino acids except glycine are optically active
(d) All amino acids except glutamic acids are optically active.     

Question. Hydrolysis of proteins give
(a) α-amino acids
(b) β-amino acids
(c) ϒ-amino acids
(d) mixture ofall, i.e.α,βϒ-amino acids     

Question. 1.78 g of an optically active L-amino acid (A) is treated with Na NO₂ /HCI at 0°C, 448 cm³ of nitrogen was at STP is evolved. A sample of protein has 0.25% of this amino acid by mass. The molar mass of the protein is
(a) 36500 g mol – 1
(b) 34500 g mol – 1
(c) 35400 g mol – 1
(d) 35600 g mol – 1     

Question. The enzyme pepsin hydrolyses 
(a) proteins to amino acids
(b) fats to fatty acids
(c) glucose to ethyl alcohol
(d) poloysaccharides to monosaccharides     

Question. An electric current is passed through an aqueous solution of a mixture of alanine (isoelectric point 6.0) glutamic acid (3.2) and arginine (10.7) buffered at pH 6. What is the fate of the three acids? 
(a) Glutamic acid migrates to anode at pH 6. Arginine present as a cation and migrates to the cathode Alanine in a dipolar ion remains uniformly distributed in solution
(b) Glutamic acid migrates to cathode and others remain uniformly distributed in solution
(c) All three remain uniformly distributed in solution 
(d) All three move to cathode     

Question. Which of the following is present in animals like cow, buffaloes etc. to digest compound like paper, cloth etc?
(a) Urease
(b) Cellulase
(c) Silicones
(d) Sucrose   

Question. The compound, which give a positive ninhydrin test and a negative Benedict’s solution test, is 
(a) a monosaccharide
(b) a disaccharide
(c) a lipid
(d) a protein       

Question. Dialysis can be used to separate 
(a) protein and starch
(b) glucose and protein
(c) glucose and NaCl
(d) glucose and fructose     

Question. Denaturation of proteins leads to the loss of its biological activity by 
(a) formation of amino acids
(b) loss of primary structure
(c) loss of both primary and secondary structures
(d) loss of both secondary and tertiary stuctures       

Question. A tripeptide is written as glycine-alanine-glycine. The correct structure of the tripeptide is 

Question. Which of the following exists as Zwitter ion ?
(a) p-aminophenol 
(b) Salicylic acid
(c) Sulphanilic acid
(d) Ethanolamine
(e) p-amino acetophenone     

Question. Which amino acid has irnidazole ring? 
(a) Alanine
(b) Leucine
(c) Tyrosine
(d) Histidine   

Question. Which amino acid has phenyl—OH group? 
(a) Lysine
(b) Arginine
(c) Proline
(d) Tyrosine       

Question. Which one of the following statements about amino acids is not trne?
(a) They are constituents of all proteins
(b) They are all high melting solids
(c) Most naturally occurring amino acids have D-configuration
(d) They are characterised by isoelectric point     

Question. Which one of the following is a conjugated protein?
(a) Phosphoprotein
(b) Glycoprotein
(c) Chromoprotein
(d) All of these     

Question. The enzyme that is used to dissolve blood clot is 
(a) trypsin
(b) renin
(c) streptokinase
(d) tyrosinase   

Question. Which destroy antigens?
(a) Insulin
(b) Antibodies
(c) Chromoprotein
(d) Phosphoprotein   

Question. The a-amino acid which does not give purple colour in the ninhydrin test is 
(a) proline
(b) glycine
(c) lysine
(d) aspartic acid     

Question. Which of the following will explain synthesis of RNA?
(a) Translation
(b) Coagulation 
(c) Transcription
(d) Replication     

Question. In an alkaline medium, glycine predominantly exists as/in a/an 
(a) cation
(b) anion
(c) Zwitter ion
(d) covalent form   

Question. The amino acid which is not optically active is
(a) lactic acid
(b) serine
(c) alanine
(d) glycine   

Question. The main structural feature of protein is 
(a) ester linkage
(b) ether linkage
(c) peptide linkage
(d) All of these   

Question. The presence or absence of hydroxy group on which carbon atom of sugar differentiates RNA and DNA ?
(a) 1st
(b) 2nd 
(c) 3rd
(d) 4th     

Question. The correct statement in respect of protein haemoglobin is that it 
(a) functions as a catalyst for biological reactions
(b) maintains blood sugar level
(c) act as an oxygen carrier in the blood
(d) forms antibodies and offers resistance to diseases 

Question. Which of the following is an amphoteric acid?
(a) Glycine
(b) Salicylic acid
(c) Benzoic acid
(d) Citric acid       

Question. At pH = 4, glycine exists as
(a) H₃N⁺—CH₂ — COO^–
(b) H₃N⁺—CH₂ — COOH
(c) H₂N—CH₂ — COOH
(d) H₂N—CH₂ — COO^–       

Question. Polypeptides having molecular weights above 10000 are known as 
(a) amino acids
(b) hormones
(c) proteins
(d) terminal amino acids   

Question. The sugar moiety present RNA molecule is 
(a) β-D-2-deoxyribose
(b) β-D-galactose
(c) β-D-fructofuranose
(d) β-D-ribose
(e) β-D-glucopyranose     

Question. The secondary structure of a protein refers to 
(a) α-helical backbone
(b) hydrophobic interactions
(c) sequence of a -amino acids
(d) fixed configmatjon of the polypeptide backbone       

Question. Which one is the correct representation of peptide bond?

Question. In alkaline medium, alanine exits predominantly as
(a) anion
(b) Zwitter ion
(c) cation
(d) covalent form 

Question. Give the pOH range for the isoelectric point of the amphoteric ion of an amino acid 
(a) 5.5 to 6.3
(b) 2.5 to 5.0
(c) 7.7 to 8.5
(d) 9.0 to 10.7     

Question. In aqueous solution, amino acids mostly exist as 
(a) NH₂ — CHR — COOH
(b) NH₂ — CHR — COO^–
(c) NH⁺₃ — CHR — COOH
(d) NH⁺₃ — CHR — COO^–       

Question. An example of a sulphur containing amino acid is 
(a) lysine
(b) serine
(c) cysteine
(d) tyrosine     

Question. The product formed in the reaction of glycine with benzoyl chloride+ aq. NaOH is 
(a) PhCOCH₂NH₂
(b) PhCH₂NH₂
(c) PhCONHCH₃
(d) PhCONHCH₂CO₂H       

Question. Which one of the following structures represents the peptide chain ?

Question. RNA contains
(a) ribose sugar and thymine
(b) ribose sugar and uracil
(c) deoxyribose sugar and uracil
(d) deoxyribose sugar and thymine 

Question. Zwitter ion is formed by
(a) aniline
(b) acetanilide
(c) benzoic acid
(d) glycine   

Question. Amino acids have peptide linkage which is 
(a) —CO—NH—
(b) —C—NH₂
(c) SO—NH—
(d) —CO—N—     

Question. Pick out the one which does not belong to the family.
(a) Pepsin
(b) Cellulose
(c) Ptyalin
(d) Lipase       

Question. If one strand of DNA has the sequence TATGACTG, the sequence in the complimentary strand would be 
(a) ATACAC T C
(b) ACGTTGAC
(c) ATACTGAC
(d) ATACTGCA   

Question. An achiral amino acid
(a) alanine
(b) valine
(c) leucine
(d) glycine       

Question. Protein gives blue colour with 
(a) benedict reagent
(b) iodine solution
(c) ninhydrin
(d) biurete 

Question. Which one is not a constituent of nucleic acid? 
(a) Uracil
(b) Guanidine
(c) Phosphoric acid
(d) Ribose sugar 

Question. The reason for double helical structure of DNA is operation of 
(a) van der Waals’ forces
(b) dipole-dipole interaction
(c) hydrogen bonding
(d) electrostatic attractions   

Question. Which of the following hormone, is responsible for the growth of animals? 
(a) Auxin
(b) Insulin
(c) Adrenaline
(d) Somatotropin     

Question. Which of the following is true?
(a) Nucleoside + phosphoester bond= nucleotide
(b) DNA’s are nucleotide and RNA’s are nucleoside
(c) Nucleotide + phosphoester bond= nucleoside
(d) None of the above   

Question. Which of the following biomolecules acts as specific catalysts in biological reaction ? 
(a) Carbohydrates
(b) Lipids
(c) Vitamins
(d) Enzymes     

Question. Monomer of nucleic acid is
(a) nucleotides
(b) nucleoxides
(c) aminoacids
(d) carboxylic acid   

Question. Metabolic function in hwnan bodies is carried out by
(a) lipids
(b) peptides 
(c) nucleic acid
(d) enzymes   

Question. A nanopeptide contains …. .. peptide linkages. 
(a) 10
(b) 8
(c) 9
(d) 18     

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   

Question. Peptides are formed from
(a) aliphatic amines
(c) a -amino acids
(b) carbohydrates
(d) aromatic amines   

Question. In DNA, the consecutive deoxynucleotides are connected via 
(a) phosphocliester linkage
(b) phosphomonoester linkage
(c) phosphotriester linkage
(d) amide linkage     

Question. Proteins are 
(a) polypeptides with low molecular weights
(b) polypeptides with high molecular weights
(c) polymers of amides
(d) polymers of secondary amines     

Question. Progesterone is secreted by … . . . . 
(a) thyroid
(b) ovaries
(c) adrenal
(d) testes