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

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
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Answer : B
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The rage limiting step cholesterol biosynthesis is (A) Squalene synthetase (B) Mevalonate kinase (C) HMG CoA synthetase (D) HMG CoA reductase

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

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 : 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

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 : 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

A hydrocarbon formed in cholesterol synthesis is (A) Mevalonate (B) HMG CoA (C) Squalene (D) Zymosterol

Description : A hydrocarbon formed in cholesterol synthesis is (A) Mevalonate (B) HMG CoA (C) Squalene (D) Zymosterol

Last Answer : Answer : C

Cholesterol by a feed back mechanism inhibits the activity of (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Thilase (D) Mevalonate kinase

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

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 : 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

Last Answer : Answer : D

HMG-CoA is converted to mevalonate by reduction catalysed by (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Mevalonate kinase (D) Thiolase

Description : HMG-CoA is converted to mevalonate by reduction catalysed by (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Mevalonate kinase (D) Thiolase

Last Answer : Answer : B

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 : 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

Last Answer : Answer : B

In the pathway leading to biosynthesis of acetoacetate from acetyl-CoA in liver, the immediate precursor of aceotacetate is (A) Acetoacetyl-CoA (B) 3-Hydroxybutyryl-CoA (C) 3-Hydroxy-3-methyl-glutaryl-CoA (D) 3-Hydroxybutyrate

Description : In the pathway leading to biosynthesis of acetoacetate from acetyl-CoA in liver, the immediate precursor of aceotacetate is (A) Acetoacetyl-CoA (B) 3-Hydroxybutyryl-CoA (C) 3-Hydroxy-3-methyl-glutaryl-CoA (D) 3-Hydroxybutyrate

Last Answer : Answer : A

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 : 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

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 : 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

Last Answer : Answer : D

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 : 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

Last Answer : Answer : D

Two molecules of acetyl-CoA condense to form acetoacetyl-CoA catalysed by (A) Thiolase (B) Kinase (C) Reductase (D) Isomerase

Description : Two molecules of acetyl-CoA condense to form acetoacetyl-CoA catalysed by (A) Thiolase (B) Kinase (C) Reductase (D) Isomerase

Last Answer : Answer : A

The starting material for ketogenesis is (A) Acyl-CoA (B) Acetyl-CoA (C) Acetoacetyl-CoA (D) Malonyl-CoA

Description : The starting material for ketogenesis is (A) Acyl-CoA (B) Acetyl-CoA (C) Acetoacetyl-CoA (D) Malonyl-CoA

Last Answer : Answer : C

Fatty acids with odd number of carbon atoms yield acetyl-CoA and a molecule of (A) Succinyl-CoA (B) Propionyl-CoA (C) Malonyl-CoA (D) Acetoacetyl-CoA

Description : Fatty acids with odd number of carbon atoms yield acetyl-CoA and a molecule of (A) Succinyl-CoA (B) Propionyl-CoA (C) Malonyl-CoA (D) Acetoacetyl-CoA

Last Answer : Answer : B

While citrate is converted to isocitrate in the mitochondria, it is converted to _______ in the cytosol. (A) Acetyl CoA + oxaloacetate (B) Acetyl CoA + malonyl CoA (C) Acetyl CoA + Pyruvate (D) Acetyl CoA + acetoacetyl CoA

Description : While citrate is converted to isocitrate in the mitochondria, it is converted to _______ in the cytosol. (A) Acetyl CoA + oxaloacetate (B) Acetyl CoA + malonyl CoA (C) Acetyl CoA + Pyruvate (D) Acetyl CoA + acetoacetyl CoA

Last Answer : Answer : A

Propionyl CoA formed oxidation of fatty acids having an odd number of carbon atoms is converted into (A) Acetyl CoA (B) Acetoacetyl CoA (C) D-Methylmalonyl CoA (D) Butyryl CoA

Description : Propionyl CoA formed oxidation of fatty acids having an odd number of carbon atoms is converted into (A) Acetyl CoA (B) Acetoacetyl CoA (C) D-Methylmalonyl CoA (D) Butyryl CoA

Last Answer : Answer : C

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 : 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

Last Answer : Answer : A

Insulin decreases the activity of (A) cAMP dependent protein kinase (B) HMG CoA-reductas (C) Phosphodiesterase (D) Acetyl CoA-carboxylase

Description : Insulin decreases the activity of (A) cAMP dependent protein kinase (B) HMG CoA-reductas (C) Phosphodiesterase (D) Acetyl CoA-carboxylase

Last Answer : Answer : A

Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165

Description : Thiamine is essential for (A) Pyruvate dehydrogenase (B) Isocitrate dehydrogenase (C) Succinate dehydrogenase (D) Acetyl CoA synthetase ENZYMES 165

Last Answer : Answer : B

Carboxylation of acetyl-CoA to malonylCoA requires the enzyme: (A) Acetyl-CoA carboxylase (B) Pyruvate carboxylase (C) Acetyl transacylase (D) Acyl CoA-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

The initial step of the citric acid cycle is (A) Conversion of pyruvate to acetyl-CoA (B) Condensation of acetyl-CoA with oxaloacetate (C) Conversion of citrate to isocitrate (D) Formation of α -ketoglutarate catalysed by isocitrate dehydrogenase

Description : The initial step of the citric acid cycle is (A) Conversion of pyruvate to acetyl-CoA (B) Condensation of acetyl-CoA with oxaloacetate (C) Conversion of citrate to isocitrate (D) Formation of α -ketoglutarate catalysed by isocitrate dehydrogenase

Last Answer : Answer : B

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 : 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

The cyclisation of squalene in mammals results in the direct formation of the sterol. (A) Cholesterol (B) Lanosterol (C) Sistosterol (D) Zymosterol

Description : The cyclisation of squalene in mammals results in the direct formation of the sterol. (A) Cholesterol (B) Lanosterol (C) Sistosterol (D) Zymosterol

Last Answer : Answer : B

A key substance in the committed step of pyrimidines biosynthesis is (A) Ribose-5-phosphate (B) Carbamoyl phosphate (C) ATP (D) Glutamine

Description : A key substance in the committed step of pyrimidines biosynthesis is (A) Ribose-5-phosphate (B) Carbamoyl phosphate (C) ATP (D) Glutamine

Last Answer : Answer : B

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 : 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

Last Answer : Answer : B

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

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

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

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

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

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

The rate limiting step in cholesterol biosynthesis is one of the followings : (A) LDL-receptor concentration (B) VLDL secretion (C) Mevalonic acid formation (D) Co-enzyme A formation

Description : The rate limiting step in cholesterol biosynthesis is one of the followings : (A) LDL-receptor concentration (B) VLDL secretion (C) Mevalonic acid formation (D) Co-enzyme A formation

Last Answer : (C) Mevalonic acid formation

The formation of ∆2-trans-enoyl-CoA from acyl-CoA requires the enzyme: (A) Acyl-CoA synthetase (B) Acyl-CoA dehydrogenase (C) 3-Hydroxy acyl-CoA dehydrogenase (D) Thiolase

Description : The formation of ∆2-trans-enoyl-CoA from acyl-CoA requires the enzyme: (A) Acyl-CoA synthetase (B) Acyl-CoA dehydrogenase (C) 3-Hydroxy acyl-CoA dehydrogenase (D) Thiolase

Last Answer : Answer : B

The source of all the carbon atoms in cholesterol is (A) Acetyl-CoA (B) Bicarbonate (C) Propionyl-CoA (D) Succinyl-CoA

Description : The source of all the carbon atoms in cholesterol is (A) Acetyl-CoA (B) Bicarbonate (C) Propionyl-CoA (D) Succinyl-CoA

Last Answer : Answer : A

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 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

Last Answer : Answer : A

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 formed from pyruvate can be used for the synthesis of all the following except (A) Glucose (B) Fatty acids (C) Cholesterol (D) Steroid hormones

Last Answer : Answer : A

Acetyl CoA is not used for the synthesis of (A) Fatty acid (B) Cholesterol (C) Pyruvic acid (D) Citric acid

Description : Acetyl CoA is not used for the synthesis of (A) Fatty acid (B) Cholesterol (C) Pyruvic acid (D) Citric acid

Last Answer : C

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 rate limiting reaction in the lipogenic pathway is (A) Acetyl-CoA carboxylase step (B) Ketoacyl synthase step (C) Ketoacyl reductase step (D) Hydratase step

Last Answer : Answer : A

In the biosynthesis of testosterone the rate limiting step is conversion of (A) Cholesterol to pregnenolone (B) Pregnenolone to progesterone (C) Progesterone to 17 α-hydroxy progesterone (D) 17 α-Hydroxy progesterone to androstenedione

Description : In the biosynthesis of testosterone the rate limiting step is conversion of (A) Cholesterol to pregnenolone (B) Pregnenolone to progesterone (C) Progesterone to 17 α-hydroxy progesterone (D) 17 α-Hydroxy progesterone to androstenedione

Last Answer : Answer : A

What is the rate-limiting-step in the cholesterol biosynthesis?

Description : What is the rate-limiting-step in the cholesterol biosynthesis? 

Last Answer : HMG CoA reductase. 

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 : 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

Last Answer : Answer : A

The coenzyme not involved in the formation of acetyl-CoA from pyruvate is (A) TPP (B) Biotin (C) NAD (D) FAD

Description : The coenzyme not involved in the formation of acetyl-CoA from pyruvate is (A) TPP (B) Biotin (C) NAD (D) FAD

Last Answer : Answer : B

Fatty acids can not be converted into carbohydrates in the body, as the following reaction is not possible: (A) Conversion of glucose-6-phosphate into glucose (B) Fructose 1, 6 diphosphate to fructose-6- phosphate (C) Transformation of acetyl CoA to pyruvate (D) Formation of acetyl CoA from fatty acids

Description : Fatty acids can not be converted into carbohydrates in the body, as the following reaction is not possible: (A) Conversion of glucose-6-phosphate into glucose (B) Fructose 1, 6 diphosphate to ... phosphate (C) Transformation of acetyl CoA to pyruvate (D) Formation of acetyl CoA from fatty acids

Last Answer : Answer : C

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) In the conversion of acetyl CoA to malonyl CoA (D) In the formation of acetyl CoA from 1 carbon intermediates

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

Last Answer : Answer : C

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 : 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

Last Answer : Answer : D

The formation of citrate from oxalo acetate and acetyl CoA is (A) Oxidation (B) Reduction (C) Condensation (D) Hydrolysis CARBOHYDRATES AND CARBOHYDRATE METABOLISM 17

Description : The formation of citrate from oxalo acetate and acetyl CoA is (A) Oxidation (B) Reduction (C) Condensation (D) Hydrolysis CARBOHYDRATES AND CARBOHYDRATE METABOLISM 17

Last Answer : C

Fatty acids cannot be converted into carbohydrates in the body as the following reaction is not possible. (A) Conversion of glucose-6-phosphate into glucose (B) Fructose 1,6-bisphosphate to fructose-6- phosphate (C) Transformation of acetyl CoA to pyruvate (D) Formation of acetyl CoA from fatty acids

Description : Fatty acids cannot be converted into carbohydrates in the body as the following reaction is not possible. (A) Conversion of glucose-6-phosphate into glucose (B) Fructose 1,6-bisphosphate to fructose- ... (C) Transformation of acetyl CoA to pyruvate (D) Formation of acetyl CoA from fatty acids

Last Answer : C

HMG-CoA reductase activity is increased by administration of the hormone: (A) Insulin (B) Glucagon (C) Epinephrine (D) Glucocorticoids

Description : HMG-CoA reductase activity is increased by administration of the hormone: (A) Insulin (B) Glucagon (C) Epinephrine (D) Glucocorticoids

Last Answer : Answer : A

The activity of HMG-CoA reductase is inhibited by (A) A fungal inhibitor mevastatin (B) Probucol (C) Nicotinic acid (D) Clofibrate

Description : The activity of HMG-CoA reductase is inhibited by (A) A fungal inhibitor mevastatin (B) Probucol (C) Nicotinic acid (D) Clofibrate

Last Answer : Answer : A

For reduction enzyme HMG-CoA reductase requires cofactor: (A) NADPH (B) NADP (C) NAD (D) FAD

Description : For reduction enzyme HMG-CoA reductase requires cofactor: (A) NADPH (B) NADP (C) NAD (D) FAD

Last Answer : Answer : A

NAD is required as a coenzyme for (A) Malate dehydrogenase (B) Succinate dehydrogenase (C) Glucose-6-phosphate dehydrogenase (D) HMG CoA reductae

Description : NAD is required as a coenzyme for (A) Malate dehydrogenase (B) Succinate dehydrogenase (C) Glucose-6-phosphate dehydrogenase (D) HMG CoA reductae

Last Answer : Answer : A

What is HMG CoA synthase?

Description : What is HMG CoA synthase?

Last Answer : It is the rate-limiting-enzyme in ketogenesis pathway.