Description : N-terminal amino acids of a polypeptide are estimated by (A) Edmann reaction (B) Sanger’s reagent (C) Formaldehyde test (D) Ninhydrine reaction
Last Answer : Answer : A
Description : Which of the following gives a positive Ninhydrin test? (A) Reducing sugar (B) Triglycerides (C) α-amino acids (D) Phospholipids
Last Answer : Answer : C
Description : Xanthoproteic test is positive in proteins containing (A) Sulphur amino acids (B) α-Amino acids (C) Aromatic amino acids (D) Aliphatic amino acids
Description : Will amino acids give a positive biuret test?
Last Answer : No. This needs a minimum of two peptide bonds.
Description : Thyroid stimulating hormone is a dimer. The α-subunits of TSH, LH, FSH are identical. Thus the biological specificity must therefore be β subunit in which the number of amino acids is (A) 78 (B) 112 (C) 130 (D) 199
Last Answer : Answer : B
Description : All of the following intermediates of citric acid cycle can be formed from amino acids except (A) α-Ketoglutarate (B) Fumarate (C) Malate (D) Oxaloacetate
Description : Thiamin diphosphate is required for oxidative decarboxylation of (A) α-Keto acids (B) α-Amino acids (C) Fatty acids (D) All of these
Description : All α-amino acids have one asymmetric carbon atom except (A) Arginine (B) Glycine (C) Aspartic acid (D) Histidine
Description : α-helix is disrupted by certain amino acids like (A) Proline (B) Arginine (C) Histidine (D) Lysine
Description : Each turn of α-helix contains the number of amino acids (A) 2.8 (B) 3.2 (C) 3.4 (D) 3.6
Last Answer : Answer : D
Description : Ninhydrin with evolution of CO2 forms a blue complex with (A) Peptide bond (B) α-Amino acids (C) Serotonin (D) Histamine
Description : Proteins contain (A) Only L- α - amino acids (B) Only D-amino acids (C) DL-Amino acids (D) Both (A) and (B)
Description : Million’s test is positive for (A) Phenylalanine (B) Glycine (C) Tyrosine (D) Proline
Description : Which one of the following is the correct matching of the site of action on the given substrate, the enzyme acting upon it and the end product? (a) Small intestine : Proteins Pepsin → ... Trypsin → Monoglycerides (d) Small intestine : Starch α-Amylase → Disaccharide (maltose)
Last Answer : (d) Small intestine : Starch α-Amylase → Disaccharide
Description : Amino acids are mostly synthesised from (a) mineral salts (b) fatty acids (c) volatile acids (d) α-ketoglutaric acid.
Last Answer : (d) α-ketoglutaric acid.
Description : Which of the following reactions is suitable for the preparation of α-amino acids? (a) Schmidt reaction (b) Hofmann's degradation of amides (c) Strecker's synthesis (b) Reduction of nitro compounds
Last Answer : Strecker's synthesis
Description : The α-carbon of all the amino acids is a chirality center except for __________. (a) Glycine (b) Threonine (c) Proline (d) Aspartic acid
Last Answer : Glycine
Description : The amino acids in which the R groups have a net positive charge at pH 7.0 are (A) Lysine, Arginine, Histidine (B) Lysine, Aspargine (C) Histidine, Aspargine (D) Glutamine, Arginine
Description : The true statement about solutions of amino acids at physiological pH is (A) All amino acids contain both positive and negative charges (B) All amino acids contain positively charged side chains ... amino acids contain only positive charge (D) All amino acids contain negatively charged side chains
Description : At neutral pH, a mixture of amino acids in solution would be predominantly: (A) Dipolar ions (B) Nonpolar molecules (C) Positive and monovalent (D) Hydrophobic
Description : The true statement about solutions of amino acids at physiological pH is (A) All amino acids contain both positive and negative charges (B) All amino acids contain positively charged side chains ... amino acids contain only positive Charge (D) All amino acids contain negatively charged side chains
Last Answer : (A) All amino acids contain both positive and negative charges
Last Answer : (A) Dipolar ions
Description : Which of the following would give a positive Tollen’s test? (a) α-D-glucopyranose (b) methyl β-D-glucopyranoside (c) sucrose (d) methyl α-D-ribofuranoside
Last Answer : α-D-glucopyranose
Description : For synthesis of CTP and UTP, the amino group comes from (A) Amide group of Asparagine (B) Amide group of glutamine (C) α-Amino group of glutamine (D) α-Amino group of glutamate
Description : The nucleophilic attack on the esterified carboxyl group of the peptidyl-tRNA occupying the P site and the α-amino group of the new amino acyl tRNA, the number of ATP required by the amino acid on the charged tRNA is (A) Zero (B) One (C) Two (D) Four
Description : The α-amino group of the new amino acyl tRNA in the A site carries out a nucleophilic attack on the esterified carboxyl group of the peptidyl tRNA occupying the P site. This reaction is catalysed by (A) DNA polymerase (B) RNA polymerase (C) Peptidyl transferase (D) DNA ligase
Description : In the biosynthesis of the iron protoporphyrin, the product of the condensation between succinyl-CoA and glycine is (A) α-Amino β-ketoadipic acid (B) δ-Aminolevulinate (C) Hydroxymethylbilane (D) Uroporphyrinogen I
Description : A molecule of CO2 is captured by biotin when it acts as coenzyme for carboxylation reaction. The carboxyl group is covalently attached to (A) A nitrogen (N1) of the biotin molecule (B) Sulphur of thiophene ring (C) α-Amino group of lysine (D) α-Amino group of protein
Description : In biotin-containing enzymes, the biotin is bound to the enzyme by (A) An amide linkage to carboxyl group of glutamine (B) A covalent bond with CO2 (C) An amide linkage to an amino group of lysine (D) An amide linkage to α-carboxyl group of protein
Description : The following ketoacid is involved in fixing dietary NH3 into amino acid: (A) Pyruvate (B) Oxalo acetate (C) Oxalo succinate (D) α-keto glutarate
Description : An amino acid that does not take part in α helix formation is (A) Histidine (B) Tyrosine (C) Proline (D) Tryptophan
Description : Along the α-helix each amino acid residue advances in nm by (A) 0.15 (B) 0.10 (C) 0.12 (D) 0.20
Description : Each turn of α-helix contains the amino acid residues (number): (A) 3.6 (B) 3.0 (C) 4.2 (D) 4.5
Description : An example of α-amino acid not present in proteins but essential in mammalian metabolism is (A) 3-Amino 3-hydroxypropanoic acid (B) 2-Amino 3-hydroxybutanoic acid (C) 2-Amino 4-mercaptobutanoic acid (D) 2-Amino 3-mercaptopropanoic acid
Description : Decarboxylation of α-keto acids requires (A) Thiamine pyrophosphate, FAD, NAD+ (B) Flavin mononucleotide (C) NADP+ (D) NAD+ only
Description : The principal rate limiting step in the biosynthesis of bile acids is at the (A) 7-Hydroxylase reaction (B) 12 α-Hydroxylase reaction (C) Conjugation reaction (D) Deconjugation reaction
Description : The fatty acids containing even number and odd number of carbon atoms as well as the unsaturated fatty acids are oxidized by (A) α-oxidation (B) β-oxidation (C) ω-oxidation (D) All of these
Description : Fatty acids are oxidized by (A) α -oxidation (B) β -oxidation (C) ω -oxidation (D) All of these
Description : α-Oxidation of fatty acids occurs mainly in (A) Liver (B) Brain (C) Muscles (D) Adipose tissue
Description : All the following are omega-6-fatty acids except (A) Linoleic acid (B) α-Linolenic acid (C) γ-Linolenic acid (D) Arachidonic acid
Description : Give examples of derived amino acids.
Last Answer : Hydroxy proline, hydroxy lysine, ornithine, cit- rulline, homocysteine.
Description : Give the names of aromatic amino acids.
Last Answer : Phenylalanine and tyrosine.
Description : Give examples of amino acids with hydropho- bic side chains.
Last Answer : Valine, leucine, isoleucine.
Description : When cathode rays strike a target of high atomic weight, they give rise to – 1) α -rays (2) β and γ rays (3) X-rays (4) positive rays
Last Answer : (3) X-rays Explanation: When cathode rays strike a solid target of high atomic weight and high melting point such as tungsten, molybdenum, etc, they give rise to a highly pen-etrating radiation called the X-rays (LIT Physics by Dr. P.K Aganval).
Description : Calcium absorption is inferred by (A) Fatty acids (B) Amino acids (C) Vitamin D (D) Vitamin B12
Description : Degeneracy of the genetic code denotes the existence of (A) Base triplets that do not code for any amino acids (B) Codons consisting of only two bases (C) Codons that include one or more of the unusual bases (D) Multiple codons for a single amino acid
Description : Selectins are proteins that can recognise specific (A) Carbohydrates (B) Lipids (C) Amino acids (D) Nucleotides
Description : Glycoproteins are marked for destruction by removal of their (A) Oligosaccharide prosthetic group (B) Sialic acid residues (C) Mannose residues (D) N-terminal amino acids
Description : All the following statements about recognition of a codon on mRNA by an anticodon on tRNA are correct except (A) The recognition of the third base of the codon is not very precise (B) ... degeneracy of the genetic code (D) Wobble results in incorporation of incorrect amino acids in the protein
Description : All of the following statements about nonsense codons are true except (A) They do not code for amino acids (B) They act as chain termination signals (C) They are identical in nuclear and mitochondrial DNA (D) They have no complementary anticodons