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

1 Answer

Answer :

Answer :  A

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Description : Conversion of fatty acyl-CoA to an acylCoA derivative having 2 more carbon atoms involves as acetyl donar: (A) Acetyl-CoA (B) Succinyl-CoA (C) Propionyl-CoA (D) Malonyl-CoA

Last Answer : Answer : D

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

Description : β-Oxidation of odd-carbon fatty acid chain produces (A) Succinyl CoA (B) Propionyl CoA (C) Acetyl CoA (D) Malonyl CoA

Last Answer : Answer : D

Description : In extra hepatic tissues, one mechanism for utilization of acetoacetate involves (A) Malonyl-CoA (B) Succinyl-CoA (C) Propionyl-CoA (D) Acetyl-CoA

Last Answer : Answer : B

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

Description : What are the co-enzymes required for the conversion of propionyl CoA to succinyl CoA?

Last Answer : Biotin, ATP, Vitamin B12.

Description : As a result of each oxidation a long chain fatty acid is cleaved to give (A) An acid with 3-carbon less and propionyl CoA (B) An acid with 2-carbon less and acetyl CoA (C) An acid with 2-carbon less and acetyl CoA (D) An acid with 4-carbon and butyryl CoA

Last Answer : Answer : B

Description : Propionyl CoA is formed on oxidation of (A) Monounsaturated fatty acids (B) Polyunsaturated fatty acids (C) Fatty acids with odd number of carbon atoms (D) None of these FATS AND FATTY ACID METABOLISM 83

Last Answer : Answer : C

Description : Ceramide is formed by the combination of sphingosine and (A) Acetyl-CoA (B) Acyl-CoA (C) Malonyl-CoA (D) Propionyl-CoA

Last Answer : Answer : B

Description : Biotin is a coenzyme for (A) Pyruvate carboxylase (B) Acetyl CoA carboxylase (C) Propionyl CoA carboxylase (D) All of these

Last Answer : Answer : D

Description : Which statement is wrong for Krebs' cycle? (a) There is one point in the cycle where FAD+ is reduced to FADH2. (b) During conversion of succinyl CoA to succinic acid, a molecule of GTP is synthesised. (c ... citric acid. (d) There are three points in the cycle where NAD+ is reduced to NADH + H+.

Last Answer : (c) The cycle starts with condensation of acetyl group (acetyl CoA) with pyruvic acid to yield citric acid.

Description : The carbon chain of fatty acids is shortened by 2 carbon atoms at a time. This involves successive reactions catalysed by 4-enzymes. These act the following order: (A) Acetyl CoA dehydrogenase, ... CoA dehydrogenase (D) Enoyl hydrase, β-OH acyl CoA dehydrogenase, acyl CoA dehydrogenase, thiolose,

Last Answer : Answer : B

Description : All long chain fatty acids with even number of carbon atoms are oxidized to a pool of _________ by β-oxidation. (A) CO2 (B) Propionic acid (C) Acetic acid (D) Acetyl CoA

Last Answer : Answer : D

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

Last Answer : Answer : A

Description : Mitochondrial lipogenesis requires (A) bicarbonate (B) biotin (C) acetyl CoA carboxylase (D) NADPH

Last Answer : Answer : D

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

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 : 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

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

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

Last Answer : C

Description : What is the further metabolism of propionyl CoA?

Last Answer : Propionyl CoA is first carboxylated to methyl malonyl CoA and then to form succinyl CoA. The succinyl CoA then enters TCA cycle.

Description : In the biosynthesis of heme, condensation between succinyl CoA and glycine requires (A) NAD+ (B) FAD (C) NADH + H+ (D) B6-phosphate

Last Answer : Answer : D

Description : In the biosynthesis of the iron protoporphyrin, the product of the condensation between succinyl-CoA and glycine is (A) α-Amino β-ketoadipic acid (B) δ-Aminolevulinate (C) Hydroxymethylbilane (D) Uroporphyrinogen I

Last Answer : Answer : A

Description : Heme is synthesized from (A) Succinyl-CoA and glycine (B) Active acetate and glycine (C) Active succinate and alanine (D) Active acetate and alanine

Last Answer : Answer : A

Description : Formation of succinyl-CoA from α-Ketoglutarate is inhibited by (A) Fluoroacetate (B) Arsenite (C) Fluoride (D) Iodoacetate

Last Answer : Answer : B

Description : The example of generation of a high energy phosphate at the substrate level in the citric acid cycle is the reaction: (A) Isocitrate α-Ketoglutarate (B) Succinate α-fumarate (C) Malate α-oxaloacetate (D) Succinyl CoA α-Succinate

Last Answer : Answer : D

Description : The reaction succinyl COA to succinate requires (A) CDP (B) ADP (C) GDP (D) NADP+

Last Answer : B

Description : Succinyl CoA is utilised for what purposes?

Last Answer : Porphyrin biosynthesis, activation of acetoacetate, and oxidation in TCA cycle.

Description : Succinyl CoA is generated from which substances? 

Last Answer : Odd chain fatty acids, propionic acid, valine, isoleucine, threonine.

Description : Biotin is required for the reaction of CO2 with (A) Water (B) Acetyl CoA (C) NH3 (D) Incorporation of carbon 6 in purine

Last Answer : Answer : B

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

Description : In Krebs’ cycle, the FAD precipitates as electron acceptor during the conversion of (a) fumaric acid to malic acid (b) succinic acid to fumaric acid (c) succinyl CoA to succinic acid (d) α-ketoglutarate to succinyl CoA.

Last Answer : (b) succinic acid to fumaric acid

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

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

Last Answer : Answer : B

Description : Which one of the following cofactors must be utilized during the conversion of acetyl CoA to malonyl CoA? (A) TPP (B) ACP (C) NAD+ (D) Biotin

Last Answer : Answer : D

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

Last Answer : Answer : B

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

Last Answer : Answer : D

Description : Acetyl CoA carboxylase is activated by (A) Citrate (B) Insulin (C) Both (A) and (B) (D) None of these

Last Answer : Answer : C

Description : The enzyme regulating extramitochondrial fatty acid synthesis is (A) Thioesterase (B) Acetyl CoA carboxylase (C) Acyl transferase (D) Multi-enzyme complex

Last Answer : Answer : B

Description : β-oxidation of fatty acids is inhibited by (A) NADPH (B) Acetyl CoA (C) Malonyl CoA (D) None of these

Last Answer : Answer : C

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

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

Last Answer : Answer : D

Description : End product of aerobic glycolysis is (A) Acetyl CoA (B) Lactate (C) Pyruvate (D) CO2 and H2O

Last Answer : Answer : C

Description : An allosteric inhibitor of pyruvate dehydrogenase is (A) Acetyl CoA (B) ATP (C) NADH (D) Pyruvate

Last Answer : Answer : A

Description : Conversion of pyruvate into acetyl CoA is catalysed by (A) Pyruvate dehydrogenase (B) Didrolipoyl acetyl transferase (C) Dihydrolipoyl dehydrogenase (D) All the 3 acting in concert

Last Answer : Answer : D

Description : Pyruvate is converted into acetyl-CoA by (A) Decarboxylation (B) Dehydrogenation (C) Oxidative decarboxylation (D) Oxidative deamination

Last Answer : Answer : C

Description : Acetyl-CoA can be formed from (A) Pyruvate (B) Fatty acids (C) ketone bodies (D) All of these

Last Answer : Answer : D

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