Description : Parathormone is required for the conversion of (A) Cholecalciferol into 1-hydroxycholecalciferol (B) Cholecalciferol into 25-hydroxycholecalciferol (C) 25-Hydroxycholecalciferol into calcitriol (D) Cholesterol into 7-dehydrocholesterol
Last Answer : Answer : C
Description : The most potent Vitamin D metabolite is (A) 25-Hydroxycholecalciferol (B) 1,25-Dihydroxycholecalciferol (C) 24, 25-Dihydroxycholecalciferol (D) 7-Dehydrocholesterol
Last Answer : Answer : B
Description : A provitamin D synthesized in human beings is (A) Ergosterol (B) 7-Dehydrocholesterol (C) Cholecalciferol (D) 25-Hydroxycholecalciferol
Description : The structure shown below is of (A) Cholecalciferol (B) 25-Hydroxycholecalciferol (C) Ergocalciferol (D) 7-Dehydrocholesterol
Last Answer : Answer : A
Last Answer : (B) 1,25-Dihydroxycholecalciferol
Description : Tubular reabsorption of calcium is increased by (A) Cholecalciferol (B) 25-Hydroxycholecalciferol (C) Calcitriol (D) All of these
Description : Steroid hormones are synthesised from (A) Cholesterol (B) 7-Dehydrocholesterol (C) Calcitriol (D) 7-Hydroxycholesterol
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 most active form of Vitamin D is (A) 25-Hydroxycholecalciferol (B) 1, 25-dihydroxycholecalciferol (C) 25-dihydroxyergocalciferol (D) None of these
Description : Calcitriol is (A) 1-hydroxy cholecalciferol (B) 25-hydroxy cholecalciferol (C) 24, 25-dihydroxy cholecalciferol (D) 1, 25-dihydroxy cholecalciferol
Description : Calcitriol is (A) 1-OH-cholecalciferol (B) 25-OH-cholecalciferol (C) 24, 25-diOH cholecalciferol (D) 1, 25-diOH cholecalciferol
Description : Provitamin D3 is (A) Cholecalciferol (B) Ergosterol (C) 7-Dehydrocholesterol (D) Ergocaliferol
Description : The β-ring of 7-dehydrocholesterol is cleaved to form cholecalciferol by (A) Infrared light (B) Dim light (C) Ultraviolet irridation with sunlight (D) Light of the tube lights
Description : The most suitable vitamin D preparation for vitamin D dependent rickets is: A. Calciferol B. Cholecalciferol C. Calcifediol D. Calcitriol
Last Answer : D. Calcitriol
Description : This interferes with cholesterol absorption (A) Lipoprotein lipase (B) Creatinase (C) 7-dehydrocholesterol (D) β-sitosterol
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 normal serum concentration of 24,25- dihydroxycholecalciferol in ng/ml is (A) 8–20 (B) 25–50 (C) 1–5 (D) 60–100
Description : The normal serum concentration of 1,25- dihydroxycholecalciferol in pg/ml is (A) 26–65 (B) 1–5 (C) 5–20 (D) 80–100
Description : The normal serum concentration of 25-hydroxycholecalciferol in ng/ml is (A) 0–8 (B) 60–100 (C) 100–150 (D) 8–55
Description : The active transport of ‘Ca’ is regulated by __________ which is synthesized in kidnyes. (A) Cholecalciferol (B) Ergosterol (C) 25-OH cholecalciferol (D) 1, 25-di OH-Cholecalciferol
Description : Hydroxylation of 25-hydroxy cholecalciferol is promoted by (A) Cytochrome A (B) Panthyroid hormone (C) Cytochrome b (D) cAMP
Description : Hydroxylation of 25-hydroxy cholecalciferol is promoted by (A) Cytochrome - a (B) Parathyroid hormone (C) Cytochrome-b (D) CAMP
Description : One international unit (I.U) of vitamin D is defined as the biological activity of (A) 0.025 µg of cholecalciferol (B) 0.025 µg of 7-dehydrocholecalciferol (C) 0.025 µg of ergosterol (D) 0.025 µg of ergocalciferol VITAMINS 113
Description : 6-Mercapto purine inhibits the conversion of (A) IMP→ XMP (B) Ribose 5 phosphate → PRPP (C) PRPP → 5-phospho →β -D-ribosylamine (D) Glycinamide ribosyl 5-phosphate → formylglycinamide ribosyl-5-phosphate
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 : Cholesterol by a feed back mechanism inhibits the activity of (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Thilase (D) Mevalonate kinase
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 : cis-acting elements include (A) Steroid hormones (B) Calcitriol (C) Histones (D) Silencers
Description : Hormone that bind to cell surface receptor and require the second messenger camp is (A) Antidiuretic hormone (B) Cholecystokinin (C) Calcitriol (D) Gastrin
Description : Calcitriol facilitates calcium absorption by increasing the synthesis of the following in intestinal mucosa: (A) Calcium Binding Protein (B) Alkaline Phosphatase (C) Calcium-dependent ATPase (D) All of these
Description : Calcitriol synthesis involves (A) Both liver and kidney (B) Intestine (C) Adipose tissue (D) Muscle
Description : A high plasma calcium level decreases intestinal absorption of calcium by (A) Stimulating the secretion of parathormone (B) Inhibiting the secretion of parathormone (C) Decreasing the synthesis of cholecalciferol (D) Inhibiting the secretion of thyrocalcitonin
Description : This is photo labile vitamin: (A) Thiamine (B) Riboflavin (C) Niacin (D) Cholecalciferol
Description : This is a photo-labile vitamin. (A) Thiamine (B) Riboflavin (C) Niacin (D) Cholecalciferol
Description : Dictary deficiency of this vitamin leads to night blindness: (A) Retinol (B) Niacin (C) Ascorbic acid (D) Cholecalciferol VITAMINS 125
Description : Activated lecithin cholesterol acyl transferase is essential for the conversion of (A) VLDL remnants into LDL (B) Nascent HDL into HDL (C) HDL2 into HDL3 (D) HDL3 into HDL2
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
Description : Characteristics of Vitamin D and its metabolites include which one of the following? (a) Act to decrease serum levels of calcium (b) Activation of their Vitamin D receptors increases cellular CAMP ... Vitamin D increase renal excretion of calcium (e) Vitamin D deficiency results in Pager's disease
Last Answer : Ans: C
Description : 6.2 Which hormone acts through a cytoplasmic receptor: A. Calcitriol B. Prolactin C. Vasopressin D. None of the abov
Last Answer : A.Calcitol binds to cytoplasmic membrane and enhances the absorption of Calcium by increasing the calcium binding proteins-calbindin-D proteins.
Description : Corporate executives who work in top notch companies and travel to their offices in early morning in their air conditioned cars with tinted glasses spending their entire day in their cabins are prone ... from the deficiency of: (a) calcitonin (b) cynacobalamin (c) tocopherol (d) cholecalciferol.
Last Answer : Ans:(b)
Description : The catalytic converter for conversion of SO2 to SO3 by contact process should have a feed with SO2 content between (A) 2-5 % (B) 7-10 % (C) 12-15 % (D) 20-25 %
Last Answer : (B) 7-10 %
Description : Furosemide inhibits reabsorption of sodium and chloride in (A) Proximal convoluted tubules (B) Loop of Henle (C) Distal convoluted tubules (D) Collecting ducts
Description : Amanitin the mushroom poison inhibits (A) Glycoprotein synthesis (B) ATP synthesis (C) DNA synthesis (D) mRNA synthesis
Description : The antibiotic which inhibits DNA dependent RNA polymerase is (A) Mitomycin C (B) Actinomycin d (C) Streptomycin (D) Puromycin
Description : All of the following statements about puromycin are true except (A) It is an alanyl tRNA analogue (B) It causes premature termination of protein synthesis (C) It inhibits protein synthesis in prokaryotes (D) It inhibits protein synthesis in eukaryotes
Description : Diphtheria toxin inhibits (A) Prokaryotic EF-1 (B) Prokaryotic EF-2 (C) Eukaryotic EF-1 (D) Eukaryotic EF-2
Description : Erythromycin binds to 50 S ribosomal sub unit and (A) Inhibits binding of amino acyl tRNA (B) Inhibits Peptidyl transferase activity (C) Inhibits translocation (D) Causes premature chain termination
Description : Ciprofloxacin inhibits the synthesis of (A) DNA in prokaryotes (B) DNA in prokaryotes and eukaryotes (C) RNA in prokaryotes (D) RNA in prokaryotes and eukaryotes
Description : α-Amanitin inhibits (A) DNA polymerase II of prokaryotes (B) DNA polymerase α of eukaryotes (C) RNA polymerase II of eukaryotes (D) RNA-dependent DNA polymerase
Description : Rifampicin inhibits (A) Unwinding of DNA (B) Initiation of replication (C) Initiation of translation (D) Initiation of transcription