Description : Lovastatin is a (A) Competitive inhibitor of acetyl CoA carboxylase (B) Competitive inhibitor of HMG CoA synthetase (C) Non-competitive inhibitor of HMG CoA reductase (D) Competitive inhibitor of HMG CoA reductase
Last Answer : Answer : D
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
Last Answer : Answer : C
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 : The rage limiting step cholesterol biosynthesis is (A) Squalene synthetase (B) Mevalonate kinase (C) HMG CoA synthetase (D) HMG CoA reductase
Description : Formation of acetyl CoA from pyruvate for de novo synthesis of fatty acids requires (A) Pyruvate dehydrogenase complex (B) Citrate synthetase (C) ATP citrate lyase (D) All of these
Description : The ‘Committed step’ in the biosynthesis of cholesterol from acetyl CoA is (A) Formation of acetoacetyl CoA from acetyl CoA (B) Formation of mevalonate from HMG CoA (C) Formation of HMG CoA from acetyl CoA and acetoacetyl CoA (D) Formation of squalene by squalene synthetase
Description : Carboxylation of acetyl-CoA to malonylCoA requires the enzyme: (A) Acetyl-CoA carboxylase (B) Pyruvate carboxylase (C) Acetyl transacylase (D) Acyl CoA-synthetase
Last Answer : Answer : A
Description : Acetyl CoA required for de novo synthesis of fatty acids is obtained from (A) Breakdown of existing fatty acids (B) Ketone bodies (C) Acetate (D) Pyruvate
Description : HMG-CoA is converted to mevalonate by reduction catalysed by (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Mevalonate kinase (D) Thiolase
Description : In gluconeogensis, an allosteric activator required in the synthesis of oxaloacetate from bicarbonate and pyruvate, which is catalysed by the enzyme pyruvate carboxylase is (A) Acetyl CoA (B) Succinate (C) Isocitrate (D) Citrate
Description : Insulin decreases the activity of (A) cAMP dependent protein kinase (B) HMG CoA-reductas (C) Phosphodiesterase (D) Acetyl CoA-carboxylase
Description : Acetyl CoA required for extra mitochondrial fatty acid synthesis is produced by (A) Pyruvate dehydrogenase complex (B) Citrate lyase (C) Thiolase (D) Carnitine-acyl transferase
Description : The acetyl CoA formed on β-oxidation of all long chain fatty acids is metabolized under normal circumstances to (A) CO2 and water (B) Cholesterol (C) Fatty acids (D) Ketone bodies
Description : The rate limiting reaction in the lipogenic pathway is (A) Acetyl-CoA carboxylase step (B) Ketoacyl synthase step (C) Ketoacyl reductase step (D) Hydratase step
Description : The enzyme regulating extramitochondrial fatty acid synthesis is (A) Thioesterase (B) Acetyl CoA carboxylase (C) Acyl transferase (D) Multi-enzyme complex
Description : For reduction enzyme HMG-CoA reductase requires cofactor: (A) NADPH (B) NADP (C) NAD (D) FAD
Description : All the following statements about acetyl CoA carboxylase are true except (A) It is required for de novo synthesis of fatty acids (B) It is required for mitochondrial elongation of fatty acids ( ... for microsomal elongation of fatty acids (D) Insulin converts its inactive form into its active form
Description : All the following correctly describe the intermediate 3-OH-3-methyl glutaryl CoA except (A) It is generated enzymatically in the mitochondrial matrix (B) It is formed in the cytoplasm (C) It inhibits the first step in cholesterol synthesis (D) It is involved in the synthesis of ketone bodies
Description : Select the first line hypolipidemic drug/drugs for treating hypertriglyceridemia in a subject with normal cholesterol level: A. Fibrates B. HMG-CoA reductase inhibitors C. Nicotinic acid D. Both 'A' and 'C' are correc
Last Answer : D. Both 'A' and 'C' are correct
Description : Select the most appropriate hypolipidemic drug for a patient with raised LDL-cholesterol level but normal triglyceride level: A. A HMG-CoA reductase inhibitor B. A fibric acid derivative C. Gugulipid D. Nicotinic acid
Last Answer : A. A HMG-CoA reductase inhibitor
Description : A metabolite obtained from Aspergillus terreus that can bind very tightly to HMG CoA reductase enzyme is (A) Fluvastatin (B) Cerivastatin (C) Lovastatin (D) Somatostatin
Last Answer : (C) Lovastatin
Description : Acetyl-CoA can be formed from (A) Pyruvate (B) Fatty acids (C) ketone bodies (D) All of these
Description : Which of the following products of triacylglycerol breakdown and subsequent β-Oxidation may undergo gluconeogenesis? (A) Acetyl CoA (B) Porpionyl CoA (C) All ketone bodies (D) Some amino acids
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 : Acetyl CoA carboxylase regulates fatty acid synthesis by which of the following mechanism? (A) Allosteric regulation (B) Covalent modification (C) Induction and repression (D) All of these
Description : Which of the following compound is a positive allosteric modifier of the enzyme pyruvate carboxylase? (A) Biotin (B) Acetyl CoA (C) Oxaloacetate (D) ATP
Last Answer : A
Description : A hydrocarbon formed in cholesterol synthesis is (A) Mevalonate (B) HMG CoA (C) Squalene (D) Zymosterol
Description : HMG-CoA reductase activity is increased by administration of the hormone: (A) Insulin (B) Glucagon (C) Epinephrine (D) Glucocorticoids
Description : The activity of HMG-CoA reductase is inhibited by (A) A fungal inhibitor mevastatin (B) Probucol (C) Nicotinic acid (D) Clofibrate
Description : Acetyl-CoA is the principal building block of fatty acids. It is produced within the mitochondria and does not diffuse readily into cytosol. The availability of acetyl CoA involves (A) Carnitine acyl transferase (B) Pyruvate dehydrogenase (C) Citrate lyase (D) Thiolase
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 : Choose the most potent and most efficacious LDLcholesterol lowering HMG-CoA reductase inhibitor: A. Lovastatin B. Simvastatin C. Pravastatin D. Atorvastatin
Last Answer : D. Atorvastatin
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 : Acetyl CoA is not used for the synthesis of (A) Fatty acid (B) Cholesterol (C) Pyruvic acid (D) Citric acid
Last Answer : C
Description : All the following statements about acetyl CoA carboxylase are true except: (A) It is activated by citrate (B) It is inhibited by palmitoyl CoA (C) It can undergo covalent modification (D) Its dephosphorylated form is inactive
Description : Acetyl CoA carboxylase is activated by (A) Citrate (B) Insulin (C) Both (A) and (B) (D) None of these
Description : The principal action of insulin in adipose tissue is to inhibit the activity of the (A) Hormone sensitive lipoprotein lipase (B) Glycerol phosphate acyltransferase (C) Acetyl-CoA carboxylase (D) Pyruvate dehydrogenase
Description : Fully activated pyruvate carboxylase depends upon the presence of (A) Malate and Niacin (B) Acetyl CoA and biotin (C) Acetyl CoA and thiamine pyrophosphate (D) Oxaloacetate and biotin
Description : Biotin is a coenzyme for (A) Pyruvate carboxylase (B) Acetyl CoA carboxylase (C) Propionyl CoA carboxylase (D) All of these
Description : Mitochondrial lipogenesis requires (A) bicarbonate (B) biotin (C) acetyl CoA carboxylase (D) NADPH
Description : Two molecules of acetyl-CoA condense to form acetoacetyl-CoA catalysed by (A) Thiolase (B) Kinase (C) Reductase (D) Isomerase
Description : Acetyl CoA from mitochondria is transferred to cytoplasm for the de novo synthesis of fatty acid, by which enzyme?
Last Answer : ATP citrate lyase.
Description : Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165
Description : Trimethoprim inhibits bacteria without affecting mammalian cells because: A. It does not penetrate mammalian cells B. It has high affinity for bacterial but low affinity for mammalian dihydrofolate ... bacterial folate synthetase as well as dihydrofolate reductase enzymes D. All of the above
Last Answer : B. It has high affinity for bacterial but low affinity for mammalian dihydrofolate reductase enzyme
Description : In the biosynthesis of cholesterol, the step which controls the rate and locus of metabolic regulation is (A) Geranyl pyrophosphate farnesyl pyrophosphate (B) Squalene → lanosterol (C) HMG CoA → mevalonate (D) Lanosterol → 1, 4-desmethyl lanosterol
Description : HMG CoA is formed in the metabolism of (A) Cholesterol, ketones and leucine (B) Cholesterol, fatty acid and Leucine (C) Lysine, Lecuine and Isoleucine (D) Ketones, Leucine and Lysine
Description : Jamaican vomiting sickness is due to inactivation of the enzyme (A) Pyruvate carboxylase (B) Acyl-Co-A synthetase (C) Acyl-Co-A dehydrogense (D) Thiolase
Description : Conversion of deoxyuridine monophosphate to thymidine monophosphate is catalysed by the enzyme: (A) Ribonucleotide reductase (B) Thymidylate synthetase (C) CTP synthetase (D) Orotidylic acid decarboxylase
Description : A cofactor required for the conversion of acetyl-CoA to malonyl-CoA in extramitochondrial fatty acid synthesis is (A) Biotin (B) FMN (C) NAD (D) NADP
Description : A soluble system for synthesis of fatty acids have been isolated from avian liver, required for the formation of long chain fatty acids by this system is (A) ATP (B) Acetyl CoA (C) NADPH (D) All of these