What is HMG CoA synthase?

1 Answer

Answer :

It is the rate-limiting-enzyme in ketogenesis pathway.

Related questions

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

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

Last Answer : Answer : A

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

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

Last Answer : Answer : A

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

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

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

Last Answer : Answer : C

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 : 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

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

Description : The enzyme acyl-CoA synthase catalyses the conversion of a fatty acid of an active fatty acid in the presence of (A) AMP (B) ADP (C) ATP (D) GTP

Last Answer : 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 : 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 : 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 primary biochemical lesion in homozygote with familial hypercholesterolemia (type IIa) is (A) Loss of feed back inhibition of HMG reductase (B) Loss of apolipoprotein B (C) Increased production of LDL from VLDL (D) Functional deficiency of plasma membrane receptors for LDL

Last Answer : Answer : D

Description : Protoporphyria (erythrohepatic) is characterized by the deficiency of (A) ALA synthase (B) ALA hydratase (C) Protophyrinogen oxidae (D) Ferrochelatase

Last Answer : Answer : D

Description : Hereditary coproporphyria is caused due to deficiency of (A) Protoporphyrinogen oxidase (B) ALA synthase (C) ALA dehydratase (D) Coproporphyrinogen oxidase

Last Answer : Answer : D

Description : The probable cause of porphyria cutanea tarda is deficiency of (A) Uroporphyrinogen oxidase (B) Coproporphyrinogen oxidase (C) Protoporphyrinogen oxidase (D) Uroporphyrinogen I synthase MINERAL METABOLISM 185

Last Answer : Answer : A

Description : The enzyme involved in congenial erythropoietic porphyria is (A) Uroporphyrinogen I synthase (B) Uroporphyrinogen III cosynthase (C) Protoporphyrinogen oxidase (D) Ferrochelatase

Last Answer : Answer : B

Description : Acute intermittent porphyria (paraoxymal porphyria) is caused due to deficiency of (A) Uroporphyrinogen I synthase (B) ALA synthase (C) Coproporphyrinogen oxidase (D) Uroporphyrinogen decarboxylase

Last Answer : Answer : A

Description : Many xenobiotics (A) Increase hepatic ALA synthase (B) Decrease hepatic ALA sythase (C) Increase hepatic ALA dehydrase (D) Decrease hepatic ALA dehydrase

Last Answer : Answer : A

Description : The synthesis of heme from protophyrin III is catalysed by the enzyme: (A) ALA synthase (B) Ferroreductase (C) Ferrooxidase (D) Ferrochelatase

Last Answer : Answer : D

Description : Conversion of the linear tetrapyrrole hydroxymethylbilane to uroporphyrinogen III (A) Occurs spontaneously (B) Catalysed by uroporphyrinogen I synthase (C) Catalysed by uroporphyrinogen III cosynthase (D) Catalysed by combined action of uroporphyrinogen I synthase and uroporphyrinogen III cosynthase

Last Answer : Answer : D

Description : The condensation of 2 molecules of δ-aminolevulinate dehydratase contains (A) ALA synthase (B) ALA hydratase (C) Uroporphyrinogen synthase I (D) Uroporphyrinogen synthase III

Last Answer : Answer : B

Description : In mammalian liver the rate controlling enzyme in porphyrin biosynthesis is (A) ALA synthase (B) ALA hydratase (C) Uroporphyrinogen I synthase (D) Uroporphyrinogen III cosynthase

Last Answer : Answer : A

Description : A regulator of the enzyme glucogen synthase is (A) Citric Acid (B) Pyruvate (C) Glucose-6-PO4 (D) GTP

Last Answer : Answer : C

Description : Brown adipose tissue is (A) A prominent tissue in human (B) Characterised by high content of mitochondria (C) Associated with high activity of ATP synthase (D) Characterised by low content of cytochromes

Last Answer : Answer : B

Description : In fatty acids synthase of both bacteria and mammals, ACP (acyl carrier protein) contain the vitamin: (A) Thiamin (B) Pyridoxine (C) Riboflavin (D) Pantothenic acid

Last Answer : Answer : D

Description : The fatty acid synthase complex catalyses (A) 4 sequential enzymatic steps (B) 6 sequential enzymatic steps (C) 7 sequential enzymatic steps (D) 8 sequential enzymatic steps

Last Answer : Answer : B

Description : The protein, which is in fact a multifunctional enzyme complex in higher organism is (A) Acetyl transacylase (B) Malonyl transacylase (C) 3-Hydroxy acyl-ACP dehyratase (D) Fatty acid synthase

Last Answer : Answer : D

Description : The best known cause of galactosemia is the deficiency of (A) Galactose 1-phosphate and uridyl transferase (B) Phosphoglucomutase (C) Galactokinase (D) Lactose synthase

Last Answer : Answer : A

Description : Her’s disease is characterized by deficiency of (A) Muscle phosphorylase (B) Liver phosphorylase (C) Debranching enzyme (D) Glycogen synthase

Last Answer : Answer : B

Description : Pompe ’s d isease is caused due to deficiency of (A) Lysosomal α-1→4 and 1→6-glucosidase (B) Glucose-6-phosphatase (C) Glycogen synthase (D) Phosphofructokinase

Last Answer : Answer : A

Description : Cori disease (Limit dextrinosis) is caused due to absence of (A) Branching enzyme (B) Debranching enzyme (C) Glycogen synthase (D) Phosphorylase

Last Answer : Answer : B

Description : The hormone activating the glycogen synthase activity is (A) Insulin (B) Glucagon (C) Epinephrine (D) ACTH

Last Answer : Answer : A

Description : Action of glycogen synthase is inhibited by (A) Insulin (B) Glucose (C) Mg2+ (D) Cyclic AMP

Last Answer : Answer : C

Description : Allosteric activator of glycogen synthase is (A) Glucose (B) Glucose-6-Phosphate (C) UTP (D) Glucose-1-phosphate

Last Answer : Answer : B

Description : In glycogenesis a branch point in the molecule is established by the enzyme (A) Amylo[1→ 4][1→ 6] transglucosidase (B) α [1→ 4] α [1→ 4] Glucan transferase (C) Amylo [1→ 6] glucosidase (D) Glycogen synthase

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Description : From arachidonate, synthesis of prostaglandins is catalysed by (A) Cyclooxygenase (B) Lipoxygenase (C) Thromboxane synthase (D) Isomerase

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Description : A regulator of the enzyme Glycogen synthase is (A) Citric acid (B) 2, 3 bisphosphoglycerate (C) Pyruvate (D) GTP

Last Answer : C

Description : One of the following statement is correct: (A) Glycogen synthase ‘a’ is the phosphorylated (B) cAMP converts glycogen synthase b to ‘a’ (C) Insulin converts glycogen synthase b to a (D) UDP glucose molecules interact and grow into a Glycogen tree

Last Answer : C

Description : One of the following enzymes does not change glycogen synthase a to b. (A) Glycogen synthase kinases 3, 4, 5 (B) Ca2+ calmodulin phosphorylase kinase (C) Ca2+ calmodulin dependent protein kinase (D) Glycogen phosphorylase a

Last Answer : D