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
Last Answer : Answer : C
Description : The rage limiting step cholesterol biosynthesis is (A) Squalene synthetase (B) Mevalonate kinase (C) HMG CoA synthetase (D) HMG CoA reductase
Last Answer : Answer : D
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
Last Answer : Answer : B
Description : Cholesterol by a feed back mechanism inhibits the activity of (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Thilase (D) Mevalonate kinase
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 : The cyclisation of squalene in mammals results in the direct formation of the sterol. (A) Cholesterol (B) Lanosterol (C) Sistosterol (D) Zymosterol
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 : An enzyme required for the synthesis of ketone bodies as well as cholesterol is (A) Acetyl CoA carboxylase (B) HMG CoA synthetase (C) HMG CoA reductase (D) HMG CoA lyase
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
Last Answer : Answer : A
Description : A metabolite which is common to pathways of cholesterol biosynthesis from acetyl-CoA and cholecalciferol formation from cholesterol is (A) Zymosterol (B) Lumisterol (C) Ergosterol (D) 7 Dehydrocholesterol
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 : Features of atorvastatin include the following: A. Dose to dose most potent HMG-CoA reductase inhibitor B. Higher ceiling of LDL-cholesterol lowering action than lovastatin C. Antioxidant property D. All of the above
Last Answer : D. All of the above
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 : 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 : All statements regarding 3-OH-3 methyl glutaryl CoA are true except (A) It is formed in the cytoplasm (B) Required in ketogenesis (C) Involved in synthesis of Fatty acid (D) An intermediate in cholesterol biosynthesis
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 : Acetoacetyl-CoA condenses with one more molecule of acetyl-CoA to form (A) Mevalonate (B) Acetoacetate (C) β-Hydroxybutyrate (D) 3-Hydroxy 3-methyl-glutaryl-CoA
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 : Insulin decreases the activity of (A) cAMP dependent protein kinase (B) HMG CoA-reductas (C) Phosphodiesterase (D) Acetyl CoA-carboxylase
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 : For reduction enzyme HMG-CoA reductase requires cofactor: (A) NADPH (B) NADP (C) NAD (D) FAD
Description : NAD is required as a coenzyme for (A) Malate dehydrogenase (B) Succinate dehydrogenase (C) Glucose-6-phosphate dehydrogenase (D) HMG CoA reductae
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
Description : What is HMG CoA synthase?
Last Answer : It is the rate-limiting-enzyme in ketogenesis pathway.
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 : 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 : 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 : 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 : In synthesis of Triglyceride from α-Glycero phosphate and acetyl CoA, the first intermediate formed is (A) β-diacyl glycerol (B) Acyl carnitine (C) Monoacyl glycerol(D) Phosphatidic acid
Description : De novo synthesis and oxidation of fatty acids differ in the following respect: (A) Synthesis occurs in cytosol and oxidation in mitochondria (B) Synthesis is decreased and oxidation increased by ... synthesis and FAD in oxidation (D) Malonyl CoA is formed during oxidation but not during synthesis
Description : The principal sterol excreted in feces is (A) Coprostanol (B) Zymosterol (C) Lanosterol (D) Desmosterol
Description : Which of the following statement is correct about membrane cholesterol? (A) The hydroxyl group is located near the centre of the lipid layer (B) Most of the cholesterol is in the form ... forms a rigid, planar structure (D) The hydrocarbon chain of cholesterol projects into the extracellular fluid
Description : The source of all the carbon atoms in cholesterol is (A) Acetyl-CoA (B) Bicarbonate (C) Propionyl-CoA (D) Succinyl-CoA
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 : 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 : The enzyme regulating extramitochondrial fatty acid synthesis is (A) Thioesterase (B) Acetyl CoA carboxylase (C) Acyl transferase (D) Multi-enzyme complex
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 : 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 : 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 : 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 : The synthesis of 3-hydroxy-3-methylglutaryl-CoA can occur (A) Only in mitochondria of all mammalian tissues (B) Only in the cytosol of all mammalian tissue (C) In both cytosol and mitochondria (D) In lysosomes
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 : Vitamin necessary for CoA synthesis: (A) Pantothenic acid (B) Vitamin C (C) B6 (D) B12
Description : Intermediate in the denovo synthesis of triacyl glycerols include all the following except (A) Fatty acyl CoA (B) CDP diacyl glycerol (C) Glycerol-3-phosphate (D) Lysophosphatidic acid
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 : Which of the following cofactors or their derivatives must be present for the conversion of acetyl CoA to malonyl CoA extramitochondrial fatty acid synthesis? (A) Biotin (B) FAD (C) FMN (D) ACP
Description : In the extra mitochondrial synthesis of fatty acids, CO2 is utilized (A) To keep the system anaerobic and prevent regeneration of acetyl CoA (B) In the conversion of malonyl to CoA hydroxybutyryl CoA (C ... of acetyl CoA to malonyl CoA (D) In the formation of acetyl CoA from 1 carbon intermediates
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
Description : For extramitochondrial fatty acid synthesis, acetyl CoA may be obtained from (A) Citrate (B) Isocitrate (C) Oxaloacetate (D) Succinate