Description : The active site of an enzyme is formed by (A) R group of amino acids (B) NH2 group of amino acids (C) CO group of amino acids (D) Sulphur bonds which are exposed
Last Answer : Answer : A
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
Last Answer : Answer : C
Description : The enzyme amino acyl tRNA synthetase is involved in (A) Dissociation of discharged tRNA from 80S ribosome (B) Charging of tRNA with specific amino acids (C) Termination of protein synthesis (D) Nucleophilic attack on esterified carboxyl group of peptidyl tRNA
Last Answer : Answer : B
Description : It is the only amino acid having an ionizing ‘R’ group with a pK’ near 7 and is important in the active site of some enzymes: (A) Arginine (B) Cystein (C) Cystine (D) Histidine
Last Answer : Answer : D
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 : Which of the following amino acids has a sulfur in the R group? (a) Serine (b) Cysteine (c) Asparagine (d) Tyrosine
Last Answer : Tyrosine
Description : The enzyme trypsin is specific for peptide bonds of (A) Basic amino acids (B) Acidic amino acids (C) Aromatic amino acids (D) Next to small amino acid residues
Description : The central heavy metal cobalt of vitamin B12 is coordinately bound to (A) Cyanide group (B) Amino group (C) Carboxyl group (D) Sulphide group
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 : 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 : Hydrophobic bonds are formed in protein be- tween which amino acids?
Last Answer : Valine, leucine and isoleucine residues.
Description : Enzymes contain 1. Peptide bonds 2. Amino acids 3. Halogens 4. Fatty acids The correct answers are: (a) 1 and 4 (b) 1,3 and 4 (c) 1 and 2 (d) 2, 3 and 4
Last Answer : Ans:(c)
Description : Name the Sulfur containing amino acids.
Last Answer : Cysteine and methionine.
Description : The shape of an enzyme and consequently its activity can be reversibly altered from moment to moment by (A) Heat (B) Amino acid substrate (C) Allosteric subunits (D) Sulfur substitutions
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 : One functional sub-unit of multi-enzyme complex for de novo synthesis of fatty acids contains (A) One —SH group (B) Two —SH groups (C) Three —SH groups (D) Four —SH groups FATS AND FATTY ACID METABOLISM 87
Description : De novo synthesis of fatty acids is catalysed by a multi-enzyme complex which contains (A) One-SH group (B) Two-SH groups (C) Three-SH groups (D) Four-SH groups
Description : A functional group designated—COOH is known as a/an a. Carboxyl. b. Carbonyl. c. Amino. d. Hydroxyl.
Last Answer : a. Carboxyl.
Description : What is the name given to the bond that links an amino group of one molecule of an amino acid to a carboxyl group of another amino acid?
Last Answer : ANSWER: PEPTIDE LINK or AMIDE LINK or PEPTIDE BOND
Description : Glycine is a unique amino acid because it (a) has no chiral carbon (b) has a sulfur containing R group (c) cannot form a peptide bond (d) is an essential amino acid
Last Answer : has no chiral carbon
Description : Which of the following statement(s) is/are true concerning the antibody response to an invading antigen? a. All antibodies are composed of one type of heavy and one type of light protein chain b. ... stimulus d. Immunoglobulins A, D, and E play an active role in the circulating humoral response
Last Answer : Answer: a Humoral defenses consist of antibody (immunoglobulin; Ig) and complement. All Ig classes (IgM, IgG, IgA, IgE, IgD) and IgG subclasses are composed of one type (M, G, A, E, D ... exist in smaller amounts in the circulation and do not appear to play a major role as host defense components
Description : The greater acidity of carboxylic acids compared to alcohols arises primarily from : (a) the electron-donating effect of the hydroxyl group (b) the electron-withdrawing effect of the carboxyl ... of α-hydrogens of carboxylic acids (d) the resonance stability associated with the carboxylate ion
Last Answer : the resonance stability associated with the carboxylate ion
Description : High iodine value of a lipid indicates (A) Polymerization (B) Carboxyl groups (C) Hydroxyl groups (D) Unsaturation
Description : Amino acids excepting histidine are not good buffering agents in cell because (A) They exist as zwitter ions (B) Their pk and not in the physiological pH of a cell (C) Only Histidine has pk of its R group at 6.0 unlike the others which have at a different pH (D) None of these
Description : Chymotrypsin is specific for peptide bonds containing (A) Uncharged amino acid residues (B) Acidic amino acids (C) Basic amino acid (D) Small amino acid residues
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 : For biosynthesis of proteins (A) Amino acids only are required (B) Amino acids and nucleic acids only are required (C) Amino acid, nucleic acids and ATP only are required (D) Amino acids, nucleic acids, ATP, GTP, enzymes and activators are required
Description : Lock' and Key' model of enzyme action proposed by Fisher implies that (A) The active site is flexible and adjusts to substrate (B) The active site requires removal of PO4 group ( ... complementary in shape to that of the substrate (D) Substrates change conformation prior to active site interaction
Description : Iodo-acetate inhibits enzyme by reacting with which group at the active site of the enzyme?
Last Answer : Sulfhydryl group.
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 : There are two properties of the cell necessary to maintain nonequilibrium cellular composition; the first is selectivity and the second is energy conversion. Which of the following statement(s ... transported via secondary active transport include hydrogen ions, calcium, amino acids and glucose
Last Answer : Answer: c, d The selectivity of the plasma membrane, although impressive, cannot account for the nonequilibrium composition of living cells. A cell can be maintained in a nonequilibrium state only by ... to drive the transport of a second species such as protons, calcium, amino acids, or glucose
Description : All proteins contain the (A) Same 20 amino acids (B) Different amino acids (C) 300 Amino acids occurring in nature (D) Only a few amino acids
Last Answer : (A) Same 20 amino acids
Description : The ionizable groups of amino acids are at least. (A) 1 (B) 2 (C) 3 (D) 4
Description : Which one among the following is the distinguishing factor between a pressure group and a political party? (1) Pressure groups are confined to a few, while political parties involve larger ... (4) Political parties take political stance, while pressure groups do not bother about political issues
Last Answer : (2) Pressure groups do not seek active political power, political parties do Explanation: Pressure groups do not seek active political power, political parties do. Political parties exist to gain power ... and they vote in a nonpartisan way, supporting candidates who promote their point of view.
Description : Enzyme catalyzed hydrolysis of proteins produces amino acids of the form: (A) D (B) L (C) DL (D) All of these
Description : Niacin contains a (A) Sulphydryl group (B) Carboxyl group (C) Amide group (D) All of these
Description : Reducing ability of carbohydrates is due to (A) Carboxyl group (B) Hydroxyl group (C) Enediol formation (D) Ring structure
Last Answer : A
Description : Sodium is involved in the active uptake of (A) D-Glucose (B) D-Galactose (C) L-Amino acids (D) All of these
Description : All the following amino acids are optically active except (A) Tryptophane (B) Phenylalanine (C) Valine (D) Glycine
Description : The third active process for amino acids transport involves (A) Acidic amino acids (B) Basic amino acids (C) Neutral amino acids (D) Sulphur containing amino acids
Description : The transport of amino acids regulated by active processes of different numbers: (A) 1 (B) 2 (C) 3 (D) 4
Description : Physiologically active configuration of amino acids: (A) L (B) D (C) For some amino acids it is either of two (D) Neither L nor D
Description : All amino acids are optically active except (A) Glycine (B) Serine (C) Threonine (D) Tryptophan
Description : The amino acids involved in the synthesis of creatin are (A) Arginine, glycine, active methionine (B) Arginine, alanine, glycine (C) Glycine, lysine, methionine (D) Arginine, lysine, methionine
Description : Natural L-isomers of amino acids are absorbed from intestine by (A) Passive diffusion (B) Simple diffusion (C) Faciliated diffusion(D) Active process
Description : Mineral acids are also classified as: w) carboxyl acids x) inorganic acids y) non-electrolytic acids z) oxidation acids
Last Answer : ANSWER: X -- INORGANIC ACIDS
Description : Digestion of proteins involves (a) changes in secondary structure only (b) cleavage of peptide linkages (c) removal of all carboxyl groups in the form of CO2. (d) removal of all NH2 groups in the form of NH3
Last Answer : cleavage of peptide linkages
Description : Which of the following amino acids has a heterocyclic R group? (a) Glycine (b) Threonine (c) Proline (d) Aspartic acid
Last Answer : Proline