Description : The defect in adrenal cortex responsible for lack of glucocorticoids and mineralcorticoids is (A) Androstenedione deficiency (B) 17 α -OH progesterone deficiency (C) C-21 hydroxylase deficiency (D) Testosterone deficiency HORMONE METABOLISM 209
Last Answer : Answer : C
Description : 3-β-Hydroxysteroid dehydrogenase and ∆5,4 isomerase catalyse the conversion of the weak androgen DHEA to (A) Androstenedione (B) Testosterone (C) Progesterone (D) Estrone
Last Answer : Answer : A
Description : The principal rate limiting step in the biosynthesis of bile acids is at the (A) 7-Hydroxylase reaction (B) 12 α-Hydroxylase reaction (C) Conjugation reaction (D) Deconjugation reaction
Description : What is the rate-limiting-step in the cholesterol biosynthesis?
Last Answer : HMG CoA reductase.
Description : The enzyme catalyzing conversion of androstenedione to testosterone is a (A) Oxygenase (B) Dehydrogenase (C) Isomerase (D) Decarboxylase
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
Last Answer : Answer : D
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
Description : A common intermediate in the synthesis of all the steroid hormones is (A) Pregnenolone (B) 17-Hydroxypregnenolone (C) Corticosterone (D) Progesterone
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 rate limiting step in the biosynthesis of catecholamines is (A) Decarboxylation of dihydroxyphenylalanine (B) Hydroxylation of phenylalanine (C) Hydroxylation of tyrosine (D) Oxidation of dopamine
Description : The precursor of testosterone is (A) Aldosterone (B) Methyl testosterone (C) Estrone (D) Pregnenolone
Description : An androgen which is more powerful than testosterone is (A) Androstenedione (B) Dihydrotestosterone (C) Androsterone (D) Epiandrosterone
Description : The major metabolite of progesterone is (A) Pregnenolone (B) Pregnanediol (C) Estradiol (D) Norethindrone
Description : Synthetic progesterone used in oral contraceptive is (A) Norethindrone (B) Pregnenolone (C) Androstenodione (D) Stilbestrol
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 : Lack of Glucocorticoids and mineral corticoids might be consequence of which of the following defects in the adrenal cortex? (A) Androstenadione deficiency (B) Estrone deficiency (C) 17 α-OH progesterone deficiency (D) C- α-Hydroxylase deficiency
Description : For Catecholamine biosynthesis the rate limiting enzyme is (A) DOPA decarboxylase (B) DOPAMINE β-hydroxylase (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase
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 : 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 : Precursor of ACTH is (A) Cholesterol (B) Pregnenolone (C) Corticotropin (D) Pro-opiomelanocortin
Description : Main metabolic end product of cholesterol: (A) Coprosterol (B) 5-pregnenolone (C) Bile acid (D) Glycine
Description : Choose the correct statement about lovastatin: A. It markedly lowers plasma triglyceride with little effect on cholesterol level B. It is used as an adjuvant to gemfibrozil for type III ... hypercholesterolemia D. It is a competitive inhibitor of the rate limiting step in cholesterol synthesis
Last Answer : D. It is a competitive inhibitor of the rate limiting step in cholesterol synthesis
Description : Progesterone is transported in blood by (A) Transcortin (B) Sex hormone binding globulin (C) Albumin (D) Testosterone estrogen binding globulin
Description : A common intermediate in the synthesis of cortisol and aldosterone is (A) Progesterone (B) Testosterone (C) Estradiol (D) None of these
Description : Cyclic AMP is formed from ATP by the enzyme adenylate cyclase which is activated by the hormone: (A) Insulin (B) Epinephrine (C) Testosterone (D) Progesterone
Last Answer : B
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
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
Description : The rate limiting step in catecholamine synthesis is catalysed by (A) Phenylalanine hydroxylase (B) Tyrosine hydroxylase (C) Dopa decarboxylase (D) Phenylethanolamine N-methyl transferase
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 : What is the rate-limiting-step in ketone body formation?
Last Answer : HMGCoA synthase.
Description : The hormone used as an oral contraceptive is – (1) Cortisone (2) Progesterone (3) Testosterone (4) Aldesterone
Last Answer : (2) Progesterone Explanation: It was discovered relatively long ago (1930's) that injections of progesterone were effective as a contraceptive in preventing pregnancies. Progesterone is used as a ... for creating a hostile environment for fertilization and not allowing sperm to enter the egg.
Description : Secretion of progesterone by corpus luteum is initiated by (a) testosterone (b) thyroxine (c) MSH (d) LH.
Last Answer : d) LH.
Description : Which of the following hormones will allow us to react to emergency situations? A) estrogen B) progesterone C) testosterone D) cortisol E) norepinephrine
Last Answer : E) norepinephrine
Description : The myofilaments of muscles consist primarily of two proteins. These two proteins are called: a) actin and myosin b) progesterone and testosterone c) progesterone and estrogen
Last Answer : ANSWER: A -- ACTIN AND MYOSIN
Description : The hormone used as an oral contraceptive is : (1) Cortisone (2) Progesterone (3) Testosterone (4) Aldesterone
Last Answer : Progesterone
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 : 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 : 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 : Cholesterol is the precursor for the biosynthesis of (A) fatty acid (B) prostaglandins (C) bile acids (D) sphingmyelin
Description : What is the first sterol ring formed during cholesterol biosynthesis?
Last Answer : Lanosterol.
Description : Conversion of testosterone to estradiol requires the enzyme: (A) Aromatase (B) Dehydrogenase (C) Lyase (D) Isomerase HORMONE METABOLISM 215
Description : A key substance in the committed step of pyrimidines biosynthesis is (A) Ribose-5-phosphate (B) Carbamoyl phosphate (C) ATP (D) Glutamine
Description : Women become susceptible to osteoporosis after menopause due to decreased (A) Secretion of Parathormone (B) Conversion of vitamin D into calcitriol (C) Secretion of estrogen (D) Secretion of progesterone
Description : The major mineralcorticoid is (A) Hydrocortisone (B) Aldosterone (C) Aldactone A (D) Androstenedione
Description : The predominant glucocorticoid is (A) Cortisol (B) Aldosterone (C) Dehydroephiandrosterone (D) Androstenedione
Description : Limiting reactant in a chemical reaction decides the (A) Rate constant (B) Conversion (C) Reaction speed (D) Equilibrium constant
Last Answer : (B) Conversion
Description : _______ organ participates maximum in cholesterol Biosynthesis. a. Liver. b. Intestine. c. Skin. d. Adrenal Cortex
Last Answer : a. Liver.
Description : An important finding in Histidinemia is (A) Impairment of conversion of α-Glutamate to α-ketoglutarate (B) Speech defect (C) Decreased urinary histidine level (D) Patients can not be treated by diet
Description : Conversion of testosterone to dihydrotestosterone by the enzyme 5α-reductase is required for the following actions except: A. Formation of male external genitalia in the foetus B. Prostatic hypertrophy in elderly males C. Pubertal changes in the male adolescent D. Spermatogenesis
Last Answer : D. Spermatogenesis
Description : Location and secretion of Leydig’s cells are (a) liver-cholesterol (b) ovary-estrogen (c) testis-testosterone (d) pancreas-glucagon.
Last Answer : (c) testis-testosterone