Description : An important function of vitamin A is (A) To act as coenzyme for a few enzymes (B) To play an integral role in protein synthesis (C) To prevent hemorrhages (D) To maintain the integrity of epithelial tissue
Last Answer : Answer : D
Description : Combination of apoenzyme and coenzyme produces (A) Prosthetic group (B) Holoenzyme (C) Enzyme substrate complex (D) Enzyme product complex
Last Answer : Answer : B
Description : In most metabolic pathways, all needed enzymes are arranged together in a multienzyme complex within a (A) Solution of ATP (B) Membrane (C) Quanternary protein (D) Coenzyme
Description : If a coenzyme is required in an enzyme reaction, the former usually has the function of (A) Acting as an acceptor for one of the cleavage products of the substrate (B) Enhancing the specificity ... C) Increasing the number of receptor sites of the apo enzyme (D) Activating the substrate ENZYMES 167
Last Answer : Answer : A
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 : The enzymes with which nicotinamide act as coenzyme are (A) Dehydrogenases (B) Transaminases (C) Decarboxylases (D) Carboxylases
Description : An enzyme required for the synthesis of thyroid hormones is (A) Iodinase (B) Deiodinase (C) Thyroperoxidase (D) Thyroxine synthetase
Last Answer : Answer : C
Description : Part of enzyme which combines with nonprotein part to form functional enzyme is (A) Apoenzyme (B) Coenzyme (C) Prosthetic group (D) None of these
Description : Hyperargininemia, a defect in urea synthesis develops due to deficiency of the enzyme: (A) Ornithine transcarbamoylase (B) Argininosuccinase (C) Arginase (D) Argininosuccinate synthetase ENZYMES 157
Description : The enzyme regulating extramitochondrial fatty acid synthesis is (A) Thioesterase (B) Acetyl CoA carboxylase (C) Acyl transferase (D) Multi-enzyme complex
Description : Which one of the following pairs of chemical substances, is correctly categorised? (a) Calcitonin and thymosin - Thyroid hormones (b) Pepsin and prolactin - Two digestive enzymes secreted in ... and myosin - Complex proteins in striated muscles (d) Secretin and rhodopsin - Polypeptide hormones
Last Answer : (c) Troponin and myosin - Complex proteins in striated muscles
Description : Coenzyme is (A) Often a vitamin (B) Always an inorganic compound (C) Always a protein (D) Often a metal ENZYMES 173
Description : Which one of the following enzymes requires a coenzyme derived from the vitamin whose structure is shown below? (A) Enoyl CoA hydratase (B) Phosphofructokinase (C) Glucose-6-phosphatase (D) Glucose-6-phosphate dehydrogenase
Description : Regulation of some enzymes by covalent modification involves addition or removal of (A) Acetate (B) Sulphate (C) Phosphate (D) Coenzyme
Description : Tetrahydrofolate is required as a coenzyme for the synthesis of (A) UMP (B) CMP (C) TMP (D) All of these
Description : For the synthesis of TMP from dump, a coenzyme is required which is (A) N10- Formyl tetrahydrofolate (B) N5- Methyl tetrahydrofolate (C) N5, N10- Methylene tetrahydrofolate (D) N5- Formimino tetrahydrofolate
Description : Which of the following coenzyme is required for porphyrin synthesis? (A) Coenzyme A (B) Pyridoxal phosphate (C) Both (A) and (B) (D) None of these
Description : Fatty acid synthesis takes place in the presence of the coenzyme: (A) NAD+ (B) Reduced NAD (C) NADP+ (D) Reduced NADP
Description : A coenzyme required for the synthesis of glycine from serine is (A) ATP (B) Pyridoxal phosphate (C) Tetrahydrofolate (D) NAD
Description : Consider the following statements. (A) Coenzyme or metal ion that is tightly bound to enzyme protein is called prosthetic group. (B) A complete catalytic active enzyme with its bound prosthetic group is called apoenzyme. Select the ... ) (A) is true but (B) is false. (d) Both (A) and (B) are false
Last Answer : (d) Both (A) and (B) are false.
Description : An organic substance bound to an enzyme and essential for the activity of enzyme is called (A) Holoenzyme (B) Apoenzyme (C) Coenzyme (D) Isoenzyme
Description : An inorganic ion required for the activity of an enzyme is known as (A) Activator (B) Cofactor (C) Coenzyme (D) None of these
Description : A Holoenzyme is (A) Functional unit (B) Apo enzyme (C) Coenzyme (D) All of these
Description : Biotin is a coenzyme of the enzyme (A) Carboxylase (B) Hydroxylase (C) Decarboxylase (D) Deaminase
Description : Riboflavin is a coenzyme in the reaction catalysed by the enzyme (A) Acyl CoA synthetase (B) Acyl CoA dehydrogenase (C) β-Hydroxy acyl CoA (D) Enoyl CoA dehydrogenase
Description : The following co-enzyme is needed for the oxidative decarboxylation of ketoacids: (A) NADP+ (B) TPP (C) Folate coenzyme (D) Biotin coenzyme
Last Answer : B
Description : The active site of an enzyme is formed by a few of the enzymes: (A) R groups of the amino acids (B) Amino groups of the amino acids (C) Carboxyl group of the amino acids (D) Exposed sulfur bonds
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 : Regulator gene controls chemical synthesis (Operon concept) by (a) Inhibiting transcription of mRNA (b) Inhibiting enzymes (c) Inhibiting passage of mRNA (d) Inhibiting substrate enzyme reaction
Last Answer : Ans. ((a))
Description : Induction of drug metabolizing enzymes involves: A. A conformational change in the enzyme protein to favour binding of substrate molecules B. Expression of enzyme molecules on the surface of ... C. Enhanced transport of substrate molecules into hepatocytes D. Increased synthesis of enzyme protein
Last Answer : D. Increased synthesis of enzyme protein
Description : Allosteric enzymes are A- larger than simple enzyme B- smaller than simple enzyme C- larger and more complex than simple enzyme D- .smaller than simple enzyme but not complex
Last Answer : larger and more complex than simple enzyme
Description : The major role of minor elements inside living organisms is to act as (a) co-factors of enzymes (b) building blocks of important amino acids (c) constituent of hormones (d) binder of cell structure.
Last Answer : (a) co-factors of enzymes
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
Description : Which statement is NOT true about steroid hormones? A) They include hormones such as estrogen. B) They do not bind to cell surface receptors. C) The hormone-receptor complex can enter the ... complex can bind to chromatin. E) Steroid hormones act faster than non-steroid (peptide) hormones.
Last Answer : E) Steroid hormones act faster than non-steroid (peptide) hormones.
Description : Enzymes, vitamins and hormones are common in (A) Being proteinaceous (B) Being synthesized in the body of organisms (C) Enhancing oxidative metabolism (D) Regulating metabolism
Description : Proteinous substances which catalyze biochemical reactions are known as (A) Activators (B) Catalysts (C) Enzymes (D) Hormones
Description : Which of the following statements is correct with reference to enzymes? (a) Holoenzyme = Apoenzyme + Coenzyme (b) Coenzyme = Apoenzyme + Holoenzyme (c) Holoenzyme = Coenzyme + Co-factor (d) Apoenzyme = Holoenzyme + Coenzyme
Last Answer : a) Holoenzyme = Apoenzyme + Coenzyme
Description : Enzymes combine with a ___________at the___________ site to lower the activation energy. a. Substrate; Active b. Product; Noncompetitive c. Product; Active d. Coenzyme; Active
Last Answer : a. Substrate; Active
Description : Which one of the following statements is correct , with reference to enzymes ? (1) Holoenzyme = Apoenzyme + Coenzyme (2) Coenzyme = Apoenzyme + Holoenzyme (3) Holoenzyme = Coenzyme + Co-factor (4) Apoenzyme = Holoenzyme + Coenzyme
Last Answer : (1) Holoenzyme = Apoenzyme + Coenzyme
Description : A common intermediate in the synthesis of all the steroid hormones is (A) Pregnenolone (B) 17-Hydroxypregnenolone (C) Corticosterone (D) Progesterone
Description : Acetyl CoA formed from pyruvate can be used for the synthesis of all the following except (A) Glucose (B) Fatty acids (C) Cholesterol (D) Steroid hormones
Description : DOPA is an intermediate in the synthesis of (A) Thyroid hormones (B) Catecholamines (C) Melanin (D) Catecholamines and melanin
Description : All the following statements about phenylketonuria are correct except (A) Phenylalanine cannot be converted into tyrosine (B) Urinary excretion of phenylpyruvate and phenyllactate is increased (C) It ... diet (D) It leads to decreased synthesis of thyroid hormones, catecholamines and melanin
Description : Hormone receptors that stimulate cAMP production (A) are part of a complex of two proteins that transform the external signal into internal cAMP production (B) are proteins distinct and separate from those ... binding of the hormone (D) are not very specific and bind a number of different hormones
Description : An examp le of group transferr ing coenzyme is (A) NAD+ (B) NADP+ (C) FAD (D) CoA
Description : Which of the following is not a component of coenzyme A? (A) Pantothenic acid (B) Adenylic acid (C) Acetic acid (D) Sulfhydryl group
Description : Sulphydryl group of coenzyme a is contributed by (A) β-Alanine (B) β-Aminoisobutyric acid (C) Methionine (D) Thioethanolamine
Description : Folate as a coenzyme is involved in the transfer and utilization of (A) Amino group (B) Hydroxyl group (C) Single carbon moiety (D) Amido group