Description : The a-helix of proteins is (A) A pleated structure (B) Made periodic by disulphide bridges (C) A non-periodic structure (D) Stabilised by hydrogen bonds between NH and CO groups of the main chain
Last Answer : Answer : C
Description : α-helix is stabilized by (A) Hydrogen bonds (B) Disulphide bonds (C) Salt bonds (D) Non-polar bonds
Last Answer : Answer : A
Description : α-Helix is formed by (A) Hydrogen bonds (B) Hydrophobic bonds (C) Electrostatic bonds (D) Disulphide bonds
Description : Primary structure of a protein is formed by (A) Hydrogen bonds (B) Peptide bonds (C) Disulphide bonds (D) All of these
Last Answer : Answer : B
Description : Many globular proteins are stable in solution although they lack in (A) Hydrogen bonds (B) Salt bonds (C) Non-polar bonds (D) Disulphide bonds
Last Answer : Answer : D
Description : Many globular proteins are stable in solution inspite they lack in (A) Disulphide bonds (B) Hydrogen bonds (C) Salt bonds (D) Non polar bonds
Description : The bond in proteins that is not broken under usual conditions of denaturation: (A) Hydrophobic bond (B) Hydrogen bond (C) Disulphide bond (D) Peptide bonds
Description : Proteins react with biuret reagent which is suggestive of 2 or more (A) Hydrogen bonds (B) Peptide bonds (C) Disulphide bonds (D) Hydrophobic bonds
Description : The bond in proteins that is not hydrolysed under usual conditions of denaturation: (A) Hydrophobic bond (B) Hydrogen bond (C) Disulphide bond (D) Peptide bonds
Description : Bonds that are formed between two cysteine residues is (A) Disulphide (B) Peptide (C) Electrostatic (D) Hydrophobic
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 : In quaternary structure, subunits are linked by (A) Peptide bonds (B) Disulphide bonds (C) Covalent bonds (D) Non-covalent bonds
Description : The amino terminal of all polypeptide chain at the time of synthesis in E. coli is tagged to the amino acid residue: (A) Methionine (B) Serine (C) N-formyl methinine(D) N-formal serine
Description : A chain of amino acids joined by peptide bonds is called as (a) Peptide chain (b) Polypeptide chain (c) Polyamino acid chain (d) Nucleotide chain
Last Answer : Ans. ((b))
Description : The two strands of the DNA double helix are held together by (a) Hydrogen bonds (b)C=C double bonds (c) Hydrophobic bonds (d) Peptide bonds
Last Answer : Ans:(a)
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 : A protein reacts with biuret reagent which indicates 2 or more (A) Blood clotting (B) Peptide bond (C) Disulphide bonds (D) Hydrophobic bonds
Description : Human growth hormone has (A) One polypeptide chain and one intra-chain disulphide bond (B) One polypeptide chain and two intra-chain disulphide bond (C) Two polypeptide chains joined by one disulphide bond (D) Two polypeptide chains joined by two disulphide bond
Description : What property of low-molecular weight aldehydes and ketones accounts for the magnitude of their boiling points? (a) The ability to form strong H-bonds between their molecules. (b) The ability of ... other polar molecules. (d) The ability of the carbonyl group to attract electrophiles and form bonds.
Last Answer : The ability of the polar carbonyl group to attract other polar molecules.
Description : In denaturation of proteins, the bond which is not broken: (A) Disulphide bond (B) Peptide bond (C) Hydrogen bond (D) Ionic bond
Description : A disulphide bond can be formed between (A) Two methionine residues (B) Two cysteine residues (C) A methionine and a cysteine residue (D) All of these
Description : Which of the following is the main structural feature of proteins? (a) Peptide linkage (b) Ester linkage (c) Ether linkage (d) α,β-Linkage
Last Answer : Peptide linkage
Description : Which bond is present in the primary structure of protein? (A) Ester (B) Hydrogen (C) Ionic bond (D) Peptide
Description : The number of intra-chain disulphide bonds in pro-insulin: (A) One (B) Two (C) Three (D) Four
Description : All the following statements about pepsin are correct except (A) It is smaller than pepsinogen (B) It is formed by the action of HCl on its precursor (C) Its optimum pH is 1.0–2.0 (D) It hydrolyses the C-terminal and N-terminal peptide bonds of proteins
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 : 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 : The chemical forces that bind most coenzymes and substrates to enzymes such as LDH are (A) Hydrogen bonds (B) Peptide bonds (C) Coordinate bonds (D) Covalent bonds
Description : The hydrogen bonds between peptide linkages are interfered by (A) Guanidine (B) Uric acid (C) Salicylic acid (D) Oxalic acid
Description : Denaturation of proteins results in (A) Disruption of primary structure (B) Breakdown of peptide bonds (C) Destruction of hydrogen bonds (D) Irreversible changes in the molecule
Description : The hydrogen bonds between peptide linkages of a protein molecules are interfered by (A) Guanidine (B) Uric acid (C) Oxalic acid (D) Salicylic acid
Description : Which bonds are the last to break when an enzyme is heated 1 disulphide 2 hydrogen 3 hydrophobic interactions 4 ionic?
Last Answer : ionic
Description : The two polypeptides of human insulin are linked together by (a) covalent bond (b) disulphide bridges (c) hydrogen bonds (d) phosphodiester bond.
Last Answer : (b) disulphide bridges
Description : The only correct statement about chymotrypsin is (A) It is formed from trypsin (B) Carboxypeptidase converts trypsin into chymotrypsin (C) Its optimum pH is around 7 (D) It hydrolyses peptide bonds involving basic amino acids
Description : Which of the following is the correct ranking in decreasing order of relative Boiling Point of carbonyl containing compounds? (a) primary amide > carboxylic acid >> ester ~ acyl chloride ~ aldehyde ~ ketone ... chloride ~ amide (d) carboxylic acid > amide >> ester ~ acyl chloride ~ aldehyde ~ ketone
Last Answer : primary amide > carboxylic acid >> ester ~ acyl chloride ~ aldehyde ~ ketone
Description : Why do aldehydes undergo nucleophilic addition reactions while esters undergo nucleophilic acyl substitution reactions? (a) The carbonyl carbon of an ester is more electrophilic than that of an aldehyde. (b) ... adds to an aldehyde, neither H− nor R− can be eliminated since they are strongly basic
Last Answer : Once the nucleophile adds to an aldehyde, neither H− nor R− can be eliminated since they are strongly basic
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 : Which of the following is the least likely to be involved in stabilising the three-dimensional folding of most proteins (a) Hydrogen bonds (b) Electrostatic interaction (c) Hydrophobic interaction (d) Ester bonds
Last Answer : (d) Ester bonds
Description : Tertiary structure of a protein describes (A) The order of amino acids (B) Location of disulphide bonds (C) Loop regions of proteins (D) The ways of protein folding
Description : Wolman’s disease is due to deficiency of (A) Cholesteryl ester hydrolase (B) Hexosaminidase A (C) α-Fucosidase (D) Arylsulphatase A
Description : Instead of ester link plasmalogens possess an other link in position: (A) α (B) β (C) γ (D) None of these FATS AND FATTY ACID METABOLISM 93
Description : Which of the following statements is not correct? (a) In man insulin is synthesised as a proinsulin. (b) The proinsulin has an extra peptide called C-peptide. (c) The functional insulin has A and B chains linked together by hydrogen bonds. (d) Genetically engineered insulin is produced in E.Coli.
Last Answer : (c) The functional insulin has A and B chains linked together by hydrogen bonds.
Description : The double helical structure of DNA is held together by (a) sulfur-sulfur linkages (b) peptide bonding (c) hydrogen bonding (d) glycosidic bonds
Last Answer : hydrogen bonding
Description : The α-cells of pancreas islets produce (A) Insulin (B) Glucagon (C) Somatostatin (D) Pancreatic polypeptide
Description : Type α H chain is present in (A) Ig E (B) Ig A (C) Ig M (D) Ig D
Description : The formation of a peptide bond during the elongation step of protein synthesis results in the splitting of how many high energy bonds? (A) 1 (B) 2 (C) 3 (D) 4
Description : Thiols are alcohol analogs in which the oxygen has been replaced by sulfur (e.g., CH3SH). Given the fact that the S-H bond is less polar than the O-H bond, which of the following ... (c) Hydrogen bonding forces would be the same. (d) No comparison can be made without additional information
Last Answer : Hydrogen bonding forces are weaker in thiols.
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 : α-helix is disrupted by certain amino acids like (A) Proline (B) Arginine (C) Histidine (D) Lysine
Description : The distance travelled per turn of α-helix in nm is (A) 0.34 (B) 0.44 (C) 0.54 (D) 0.64