Description : Each turn of α-helix contains the amino acid residues (number): (A) 3.6 (B) 3.0 (C) 4.2 (D) 4.5
Last Answer : Answer : A
Description : α-helix is disrupted by certain amino acids like (A) Proline (B) Arginine (C) Histidine (D) Lysine
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 : An amino acid that does not take part in α helix formation is (A) Histidine (B) Tyrosine (C) Proline (D) Tryptophan
Last Answer : Answer : C
Description : how many amino acids are there in one turn of alpha helix?
Last Answer : 3.6 amino acid.
Description : The distance travelled per turn of α-helix in nm is (A) 0.34 (B) 0.44 (C) 0.54 (D) 0.64
Description : The primary structure of a protein refers to : (a) whether the protein is fibrous or globular (b) the amino acid sequence in the polypeptide chain (c) the orientation of the amino acid side chains in space (d) the presence or absence of an α-helix
Last Answer : the amino acid sequence in the polypeptide chain
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 : Which of the following gives a positive Ninhydrin test? (A) Reducing sugar (B) Triglycerides (C) α-amino acids (D) Phospholipids
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 give positive (A) Million’s test (B) Biurete test (C) Xanthproteic test (D) Ninhydrine test
Last Answer : Answer : D
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 : All α-amino acids have one asymmetric carbon atom except (A) Arginine (B) Glycine (C) Aspartic acid (D) Histidine
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 : In protein structure the α-helix and βpleated sheets are example of (A) Primary structure (B) Secondary structure (C) Tertiary structure (D) Quaternary structure
Description : In many proteins the hydrogen bonding produces a regular coiled arrangement which is called as (A) β-Helix (B) α-Helix (C) Both (A) and (B) (D) Spiral
Description : α-helix is stabilized by (A) Hydrogen bonds (B) Disulphide bonds (C) Salt bonds (D) Non-polar bonds
Description : In many proteins the hydrogen bonding produces a regular coiled arrangement called (A) α-helix (B) β-helix (C) Both (A) and (B) (D) None of these
Description : α-Helix is formed by (A) Hydrogen bonds (B) Hydrophobic bonds (C) Electrostatic bonds (D) Disulphide bonds
Description : Both α-helix and β-pleated sheet conformation of proteins were proposed by (A) Watson and Crick (B) Pauling and Corey (C) Waugh and King (D) Y.S.Rao
Description : At the lowest energy level α-helix of polypeptide chain is stabilised (A) By hydrogen bonds formed between the H of peptide N and the carbonyl O of the residue (B) Disulphide bonds (C) Non polar bonds (D) Ester bonds
Description : In proteins the α-helix and β-pleated sheet are examples of (A) Primary structure (B) Secondary structure (C) Tertiary structure (D) Quaternary structure
Description : Which is wrong about nucleic acids? (a) DNA is single stranded in some viruses. (b) RNA is double stranded occasionally. (c) Length of one helix is 45 Å in B-DNA. (d) One turn of Z-DNA has 12 bases
Last Answer : (c) Length of one helix is 45 Å in B-DNA
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 number of nutritionally essential amino acids for man is (A) 6 (B) 8 (C) 10 (D) 12
Description : The α-Helix is held in a coiled conformation partially because of : (a) Optical activity (b) Hydrogen bonding (c) Resonance (d) Delocalization
Last Answer : Hydrogen bonding
Description : The α-Helix is a common form of (a) Primary structure (b) Tertiary structure (c) Secondary structure (d) None of these
Last Answer : Secondary structure
Description : Which of the following may characterize the “secondary structure” of proteins? (a) conformation of the protein backbone (b) α-Helix (c) parallel β-pleated sheet (d) all of the above
Last Answer : all of the above
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 : Proteins which interact with DNA and affect the rate of transcription possess the following structural motif: (A) Helix-turn-helix motif (B) Zinc finger motif (C) Leucine zipper motif (D) All of these
Description : Ten base pairs are present in one turn of the helix in (A) A-DNA (B) B-DNA (C) C-DNA (D) Z-DNA
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 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 : Urea biosynthesis occurs mainly in the liver involving the number of amino acids: (A) 3 (B) 4 (C) 5 (D) 6
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 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 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 : 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