Description : Activity of ceruloplasmin shown in vitro: (A) Reductase (B) Hydrolase (C) Ligase (D) Oxidase
Last Answer : Answer : D
Description : Methotrexate blocks the synthesis of thymidine monophosphate by inhibiting the activity of the enzyme: (A) Dihydrofolate reductase (B) Orotate phosphoribosyl transferase (C) Ribonucleotide reductase (D) Dihydroorotase
Last Answer : Answer : A
Description : Iron is a component of (A) Hemoglobin (B) Ceruloplasmin (C) Transferase (D) Transaminase
Description : Pyruvate dehydrogenase is a/an (A) Isomerase (B) Lyase (C) Ligase (D) Oxido reductase
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
Last Answer : Answer : C
Description : The enzyme hexokinase is a (A) Hydrolase (B) Oxidoreductase (C) Transferase (D) Ligase
Description : In the biosynthesis of cholesterol, the rate limiting enzyme is (A) Mevalonate kinase (B) HMG-CoA synthetase (C) HMG-CoA reductase (D) Cis-prenyl transferase
Description : Synthesis of polyunsaturated fatty acids involves the enzyme systems: (A) Acyl transferase and hydratase (B) Desaturase and elongase (C) Ketoacyl-CoA reductase and hydratase (D) Dihydroxyacetone phosphate
Description : Which of the following molecule catalyzes the transpeptidation reaction? A.RNA polymerase B.Peptidyl transferase C.DNA ligase D.DNA polymerase
Last Answer : B.Peptidyl transferase
Description : All the following statements about ceruloplasmin are correct except (A) It is a copper-containing protein (B) It possesses oxidase activity (C) It is synthesised in intestinal mucosa (D) Its plasma level is decreased inWilson’s disease
Description : Serum ferroxidase level decreases in (A) Gaucher’s disease (B) Cirrhosis of liver (C) Acute pancreatitis (D) Wilson’s disease ENZYMES 143
Description : Which mineral element controls the activity of Nitrate reductase ? (A) Fe (B) Mo (C) Zn (D) Ca
Description : HMG-CoA reductase activity is increased by administration of the hormone: (A) Insulin (B) Glucagon (C) Epinephrine (D) Glucocorticoids
Description : In biosynthesis of cholesterol triparanol inhibits the activity of the enzyme: (A) ∆24 Reductase (B) Oxidosqualene-lanosterol cyclase (C) Isomerase (D) Squalene epoxidase ENZYMES 155
Description : The activity of HMG-CoA reductase is inhibited by (A) A fungal inhibitor mevastatin (B) Probucol (C) Nicotinic acid (D) Clofibrate
Description : Cholesterol by a feed back mechanism inhibits the activity of (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Thilase (D) Mevalonate kinase
Last Answer : Answer : B
Description : Erythromycin binds to 50 S ribosomal sub unit and (A) Inhibits binding of amino acyl tRNA (B) Inhibits Peptidyl transferase activity (C) Inhibits translocation (D) Causes premature chain termination
Description : Peptidyl transferase activity of 50 S ribosomal subunits is inhibited by (A) Rifampicin (B) Cycloheximide (C) Chloramphenicol (D) Erythromycin
Description : Peptidyl transferase activity is present in (A) 40 S ribosomal subunit (B) 60 S ribosomal subunit (C) eEF-2 (D) Amino acyl tRNA
Description : All the following statements about primary gout are true except (A) Its inheritance is X-linked recessive (B) It can be due to increased activity of PRPP synthetase (C) It can be ... activity of hypoxanthine guanine phosphoribosyl transferase (D) De novo synthesis of purines is increased in it
Description : Peptidyl transferase activity is located in (A) Elongation factor (B) A charged tRNA molecule (C) Ribosomal protein (D) A soluble cytosolic protein
Description : Erythromycin acts on ribosomes and inhibit (A) Formation of initiation complex (B) Binding of aminoacyl tRNA (C) Peptidyl transferase activity (D) Translocation
Description : Streptomycin prevents synthesis of polypeptide by (A) Inhibiting initiation process (B) Releasing premature polypeptide (C) Inhibiting peptidyl transferase activity (D) Inhibiting translocation
Description : In prokaryotes, chloramphenicol (A) Causes premature release of the polypeptide chain (B) Causes misreading of the mRNA (C) Depolymerises DNA (D) Inhibits peptidyl transferase activity
Description : Insulin regulates fatty acid synthesis by (A) Dephosphorylating of acetyl CoA carboxylase (B) Activating phosphorylase (C) Inhibiting malonyl CoA formation (D) Controlling carnitine-Acyl CoA transferase activity
Description : A deficiency of copper effects the formation of normal collagen by reducing the activity of which of the following enzyme? (A) Prolyl hydroxylase (B) Lysyl oxidase (C) Lysyl hydroxylase (D) Glucosyl transferase
Description : Increased serum ornithine carabamoyl transferase activity is diagnostic of (A) Myocardial infarction (B) Hemolytic jaundice (C) Bone disease (D) Acute viral hepatitis
Description : What is ceruloplasmin? (A) Plasma protein (B) Stored form of copper (C) Both A and B (D) None of these
Description : Menke’s disease (Kinky or steel hair disease) is a X-linked disease characterized by (A) High levels of plasma copper (B) High levels of ceruloplasmin (C) Low levels of plasma copper and of ceuloplasmin (D) High level of hepatic copper
Description : In Wilson’s disease (A) Copper fails to be excreted in the bile (B) Copper level in plasma is decreased (C) Ceruloplasmin level is increased (D) Intestinal absorption of copper is decreased
Description : The normal serum concentration of ceruloplasmin in mg/100 ml varies between (A) 5–10 (B) 10–20 (C) 25–43 (D) 50–100
Description : Ceruloplasmin oxidizes (A) Copper (B) Iron (C) Both (A) and (B) (D) None of these
Description : Ceruloplasmin is absent in (A) Cirrhosis of liver (B) Wilson’s disease (C) Menke’s disease (D) Copper deficiency
Description : Proteins that carries Iron into different tissues is (A) Ceruloplasmin (B) Trans cortin (C) Mucoproteins (D) Glycoproteins
Description : A/G ratio is (A) Strength of proteins (B) ratio of serum proteins (C) ratio of ceruloplasmin (D) None of these
Description : Ceruloplasmin is (A) α1-globulin (B) α2-globulin (C) β-globulin (D) None of these
Description : An example of metalloprotein is (A) Casein (B) Ceruloplasmin (C) Gelatin (D) Salmine
Description : Molybdenum deficiency affects the activity of – (1) All of the given options (2) Chlorate reductase (3) Nitrogenase (4) Nitrate reductase
Last Answer : (4) Nitrate reductase Explanation: Numerous investigators have shown that nitrate nitrogen accumulates in higher plants and fungi which are deficient in molybdenum. In molybdenum-deficient plants grown in the ... in the decrease of free amino acids in the plants in comparison to normal plants.
Description : Molybdenum deficiency affects the activity of : (1) All of the given options (2) Chlorate reductase (3) Nitrogenase (4) Nitrate reductase
Last Answer : Nitrate reductase
Description : Unconjugated bilirubin is derived principally from: C A. glucuronyl transferase activity B. toxic liver injury C. breakdown of senescent red blood cells D. None of these
Last Answer : breakdown of senescent red blood cells
Description : In the biosynthesis of c-DNA, the joining enzyme ligase requires (A) GTP (B) ATP (C) CTP (D) UTP
Description : DNA ligase of E. coli requires which of the following co-factors? (A) FAD (B) NAD+ (C) NADP+ (D) NADH
Description : Xeroderma pigmentosum results from a defect in (A) uvr ABC excinuclease (B) DNA polymerase I (C) DNA ligase (D) All of these
Description : Damage to DNA caused by ultraviolet radiation can be repaired by (A) uvr ABC excinuclease (B) DNA polymerase I (C) DNA ligase (D) All of these
Description : Negative supercoils are introduced in DNA by (A) Helicase (B) DNA ligase (C) DNA gyrase (D) DNA polymerase III holoenzyme
Description : DNA fragments are sealed by (A) DNA polymerase II (B) DNA ligase (C) DNA gyrase (D) DNA topoisomerase II
Description : The enzyme DNA ligase (A) Introduces superhelical twists (B) Connects the end of two DNA chains (C) Unwinds the double helix (D) Synthesises RNA primers
Description : In DNA replication the enzyme required in the first step is (A) DNA directed polymerase (B) Unwinding proteins (C) DNA polymerase (D) DNA ligase
Description : Urease is a (A) Lyase (B) Ligase (C) Isomerase (D) Hydrolase
Description : Cancer cells may become resistant to amethopterin by (A) Developing mechanisms to destroy amethopterin (B) Amplification of dihydrofolate reducatse gene (C) Mutation in the dihydrofolate reductase ... is no longer inhibited by amethopterin (D) Developing alternate pathway of thymidylate synthesis