Description : Purine biosynthesis is inhibited by (A) Aminopterin (B) Tetracyclin (C) Methotrexate (D) Chloramphenicol
Last Answer : Answer : A
Description : Most hormone receptors are localized on the cell membrane and transduce hormone binding into altered levels of intracellular messengers. A limited number of intracellular receptors do exist. Which of ... protein serves as an inhibitor protein blocking the DNA-binding domain of the steroid receptor
Last Answer : Answer: a, d Although most hormone and other messenger receptors are extracellular, intracellular receptors have been identified. The hormone messengers involved for these receptors are primarily ... DNA-binding domain of the receptor. Activation involves the dissociation of the inhibitor protein
Description : Which of the following is a steroid 5α-reductase inhibitor that has been found useful in benign prostatic hypertrophy and male pattern baldness: A. Flutamide B. Finasteride C. Prazosin D. Minoxidil
Last Answer : B. Finasteride
Description : Hybridoma cells are selected by culturing them in a medium containing (A) Adenine, guanine, cytosine and thymine (B) Adenine, guanine, cytosine and uracil (C) Hypoxanthine, aminopterin and thymine (D) Hypoxanthine, aminopterin and thymidine
Last Answer : Answer : D
Description : Amethopterin and aminopterin decrease the synthesis of (A) TMP (B) UMP (C) CMP (D) All of these
Description : Carbonic anhydrase is competitively inhibited by (A) Allopurinol (B) Acetazolamide (C) Aminopterin (D) Neostigmine
Last Answer : Answer : B
Description : The anti-vitamin for para amino benzoic acid is (A) Aminopterin (B) Dicoumarol (C) INH (D) Sulphanomides
Description : An anti-vitamin for folic acid is (A) Aminopterin (B) Dicoumarol (C) Pyrithiamine (D) Isoniazid
Description : The anti-vitamin for para amino benzoic acid is (A) Aminopterin (B) Dicoumasol (C) Sulphanomides (D) Thiopamic acid
Last Answer : Answer : C
Description : The anti vitamin for para aminobenzoic acid is (A) Aminopterin (B) Dicoumarol (C) Sulphonamides (D) Thiopanic acid
Description : In the biosynthesis of c-DNA, the joining enzyme ligase requires (A) GTP (B) ATP (C) CTP (D) UTP
Description : A key substance in the committed step of pyrimidines biosynthesis is (A) Ribose-5-phosphate (B) Carbamoyl phosphate (C) ATP (D) Glutamine
Description : What is the subcellular site for the biosynthesis of proteins? (A) Chromosomes (B) Lymosomes (C) Ribosomes (D) Centrosomes
Description : In biosynthesis of proteins the chain terminating codons are (A) UAA, UAG and UGA (B) UGG, UGU and AGU (C) AAU, AAG and GAU (D) GCG, GCA and GCU
Description : The enzyme aspartate transcarbamoylase of pyrimidine biosynthesis is inhibited by (A) ATP (B) ADP (C) AMP (D) CTP
Description : An enzyme of pyrimidine nucleotides biosynthesis regulated at the genetic level by apparently coordinate repression and derepression is (A) Carbamoyl phosphate synthetase (B) Dihydroorotate dehydrogenase (C) Thymidine kinase (D) Deoxycytidine kinase
Description : An enzyme of pyrimidine nucleotide biosynthesis sensitive to allosteric regulation is (A) Aspartate transcarbamoylase (B) Dihydroorotase (C) Dihydroorotate dehydrogenase (D) Orotidylic acid decarboxylase
Description : A substrate for enzymes of pyrimidine nucleotide biosynthesis is (A) Allopurinol (B) Tetracylin (C) Chloramphenicol (D) Puromycin
Description : Pyrimidine biosynthesis begins with the formation from glutamine, ATP and CO2, of (A) Carbamoyl aspartate (B) Orotate (C) Carbamoyl phosphate (D) Dihydroorotate
Description : Pyrimidine and purine nucleoside biosynthesis share a common precursor: (A) PRPP (B) Glycine (C) Fumarate (D) Alanine
Description : In the biosynthesis of purine nucleotides the AMP feed back regulates (A) Adenylosuccinase (B) Adenylosuccinate synthetase (C) IMP dehydrogenase (D) HGPR Tase
Description : The major determinant of the overall rate of denovo purine nucleotide biosynthesis is the concentration of (A) 5-phosphoribosyl 1-pyrophosphate (B) 5-phospho β-D-ribosylamine (C) Glycinamide ribosyl-5-phosphate (D) Formylglycinamide ribosyl-5-phosphate
Description : In purine biosynthesis ring closure in the molecule formyl glycinamide ribosyl-5- phosphate requires the cofactors: (A) ADP (B) NAD (C) FAD (D) ATP and Mg++
Description : In purine biosynthesis carbon atoms at 4 and 5 position and N at 7 position are contributed by (A) Glycine (B) Glutamine (C) Alanine (D) Threonine
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 : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase
Description : For Catecholamine biosynthesis the rate limiting enzyme is (A) DOPA decarboxylase (B) DOPAMINE β-hydroxylase (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase
Description : In the biosynthesis of cortiol, the sequence of enzymes involved is (A) Hydroxylase–dehydrogenase + isomerase – hydroxylase (B) Dehydrogenase–hydroxylase–isomerase (C) Hydroxylase–lyase–dehydrogenase isomerase (D) Isomerase–lyase–hydroxylase–dehydrogenase
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
Description : In the biosynthesis of heme, condensation between succinyl CoA and glycine requires (A) NAD+ (B) FAD (C) NADH + H+ (D) B6-phosphate
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 biosynthesis of urea occurs mainly in the liver: (A) Cytosol (B) Mitochondria (C) Microsomes (D) Nuclei
Description : Identify the correct molecule which controls the biosynthesis of proteins in living organisms. (A) DNA (B) RNA (C) Purines (D) Pyrimidines
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 : 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 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 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 : The common precursor in the biosynthesis of triacylglycerol and phospholipids is (A) 1, 2-Diacylglycerol phosphate (B) 1-Acylglycerol 3-phosphate (C) Glycerol 3-phosphate (D) Dihydroxyacetone phosphate
Description : In the biosynthesis of triglycerides from glycerol 3-phosphate and acyl-CoA, the first intermediate formed is (A) 2-Monoacylglycerol (B) 1, 2-Diacylglycerol (C) Lysophosphatidic acid (D) Phosphatidic acid
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 : The pathway of glycogen biosynthesis involves a special nucleotide of glucose. In the reaction below, NuDP stands for NuDP Glucose + glycogenn → NuDP + glycogenn+1 (A) ADP (B) GDP (C) UDP (D) CDP
Description : The rage limiting step cholesterol biosynthesis is (A) Squalene synthetase (B) Mevalonate kinase (C) HMG CoA synthetase (D) HMG CoA reductase
Description : Biosynthesis of Triglyceride and Lecithine both require an intermediate: (A) Monoacyl glycerol phosphate (B) Phosphatidic acid (C) Phosphatidyl ethanol amine (D) Phosphatidyl cytidylate
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 : 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 : Cholesterol is the precursor for the biosynthesis of (A) fatty acid (B) prostaglandins (C) bile acids (D) sphingmyelin
Description : Urea biosynthesis occurs mainly in the liver involving the number of amino acids: (A) 3 (B) 4 (C) 5 (D) 6
Description : The biosynthesis of Urea occurs mainly in the Liver: (A) Cytosol (B) Microsomes (C) Nucleus (D) Mitochondria
Description : The 2 energy rich compounds needed for protein biosynthesis are (A) ATP and GTP (B) ATP and UTP (C) ATP and CTP (D) ATP and TTP