Description : Retinal is reduced to retinol by retinene reductase in presence of the coenzyme (A) NAD+ (B) NADP+ (C) NADH + H+ (D) NADPH + H+
Last Answer : Answer : C
Description : Oxaloacetate is converted to aspartic acid by (A) Reductase (B) Oxidase (C) Transminase (D) Catalase
Description : On exposure to light rhodopsin forms (A) All trans-retinal (B) Cis-retinal (C) Retinol (D) Retinoic acid
Last Answer : Answer : A
Description : Retinol and retinal are interconverted requiring dehydrogenase or reductase in the presence of (A) NAD or NADP (B) NADH + H+ (C) NADPH (D) FAD
Description : Photosensitive compound in human eye is made up of (a) opsin and retinol (b) transducin and retinene (c) guanosine and retinol (d) opsin and retinal.
Last Answer : (d) opsin and retinal.
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 : 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 : Retinal is reduced to retinol in intestinal mucosa by a specific retinaldehyde reductase utilising (A) NADPH + H+ (B) FAD (C) NAD (D) NADH + H+
Description : Vitamin K is involved in posttranslational modification of the blood clotting factors by acting as cofactor for the enzyme: (A) Carboxylase (B) Decarboxylase (C) Hydroxylase (D) Oxidase
Description : The defective enzyme in histidinemia is (A) Histidine carboxylase (B) Histidine decarboxylase (C) Histidase (D) Histidine oxidase
Description : Insulin degradation of disulfide bond formation is effected by (A) Pyruvate dehydrogenase (B) Xylitol reductase (C) Gutathione reductase (D) Xanthine oxidase
Description : Activity of ceruloplasmin shown in vitro: (A) Reductase (B) Hydrolase (C) Ligase (D) Oxidase
Description : Conversion of retinal into ritonal requires the presence of (A) NADH (B) NADPH (C) FADH2 (D) Lipoic acid
Description : In the glycolytic pathway, enolpyruvate is converted to ketopyruvate by (A) Pyruvate kinase (B) Phosphoenolpyruvate (C) Pyruvate dehydrogenase (D) Spontaneously
Description : Vitamin K is involved in posttranslational modification of the blood clotting factors by acting as cofactor for the enzyme (A) Carboxylase (B) Decarboxylase (C) Hydroxylase (D) Oxidase
Last Answer : (A) Carboxylase
Description : When light falls on rod cells (A) All-cis-retinal is converted into all-trans-retinal (B) 11-cis-retinal is converted into 11-trans-retinal (C) 11-trans-retinal is converted into all-transretinal (D) 11-cis-retinal is converted into all-trans-retinal
Description : HMG-CoA is converted to mevalonate by reduction catalysed by (A) HMG-CoA synthetase (B) HMG-CoA reductase (C) Mevalonate kinase (D) Thiolase
Description : Entropy of the system decreases, when (A) Snow melts into water (B) A gas expands spontaneously from high pressure to low pressure (C) Water is converted into ice (D) Both (B) & (C)
Last Answer : (D) Both (B) & (C)
Description : The following form of vitamin A is used in the visual cycle: (A) Retinol (B) Retinoic acid (C) Retinaldehyde (D) Retinyl acetate
Description : Retinoic acid is involved in the synthesis of (A) Rhodopsin (B) Iodopsin (C) Porphyrinopsin (D) Glycoproteins
Description : Retinoic acid can (A) Act as a photo receptor (B) Support growth and differentiation (C) Act as an anti-oxidant (D) None of these
Description : One international Unit of vitamin A is the activity present in (A) 0.3 µg of β-Carotene (B) 0.3 µg of retinol (C) 0.6 µg of retinoic acid (D) All of these
Description : Anti-oxidant activity is present in (A) β-Carotene (B) Retinol (C) Retinoic acid (D) All of these
Description : Retinoic acid participates in the synthesis of (A) Iodopsin (B) Rhodopsin (C) Glycoprotein (D) Cardiolipin
Description : Conversion of β-carotene into retinal requires the presence of (A) β-Carotene dioxygenase (B) Bile salts (C) Molecular oxygen (D) All of these
Description : Fully activated pyruvate carboxylase depends upon the presence of (A) Malate and Niacin (B) Acetyl CoA and biotin (C) Acetyl CoA and thiamine pyrophosphate (D) Oxaloacetate and biotin
Description : In presence of the following cofactor, pyruvate carboxylase converts pyruvate to oxaloacetate: (A) ATP, Protein and CO2 (B) CO2 and ATP (C) CO2 (D) Protein
Last Answer : A
Description : Metalloenzyme-retinene for polymerization of insulin is (A) Copper (B) Zinc (C) Cobalt (D) Manganese
Description : During phototransduction: a. hyperpolarisation occurs due to closure of the sodium channels b. 11-cis-retinal molecules are converted to all-trans-retinal c. transducin, a G protein converts GDP to GTP d. all above
Last Answer : all above
Description : The drug, Interleukin-2, is an example of which type of biologic response modifier? a) Cytokine Other cytokines include interferon alfa and filgrastim. b) Monoclonal antibodies Monoclonal ... an example of a retinoid. d) Antimetabolites Antimetabolites are cell cycle-specific antineoplastic agents.
Last Answer : a) Cytokine Other cytokines include interferon alfa and filgrastim.
Last Answer : (A) β-Carotene
Description : In what vitamin would retinoic acid be found?
Last Answer : ANSWER: VITAMIN A
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
Description : In conversion of lactic acid to glucose, three reactions of glycolytic pathway are circumvented, which of the following enzymes do not participate? (A) Pyruvate carboxylase (B) Phosphoenol pyruvate carboxy kinase (C) Pyruvate kinase (D) Glucose-6-phosphatase
Description : The enzyme regulating extramitochondrial fatty acid synthesis is (A) Thioesterase (B) Acetyl CoA carboxylase (C) Acyl transferase (D) Multi-enzyme complex
Description : Acetyl CoA carboxylase regulates fatty acid synthesis by which of the following mechanism? (A) Allosteric regulation (B) Covalent modification (C) Induction and repression (D) All of these
Description : In conversion of Lactic acid to Glucose, three reactions of Glycolytic pathway are circumvented, which of the following enzymes do not participate? (A) Pyruvate Carboxylase (B) Phosphoenol pyruvate carboxy kinase (C) Pyruvate kinase (D) Glucose-6-phosphatase
Last Answer : C
Description : Amplification of dihydrofolate reductase gene in a cancer cell makes the cell (A) Susceptible to folic acid deficiency (B) Less malignant (C) Resistant to amethopterin therapy (D) Responsive to amethopterin therapy
Description : Amplification of dihydrofolate reductase gene may be brought about by (A) High concentrations of folic acid (B) Deficiency of folic acid (C) Low concentration of thymidylate (D) Amethopterin
Description : Conversion of deoxyuridine monophosphate to thymidine monophosphate is catalysed by the enzyme: (A) Ribonucleotide reductase (B) Thymidylate synthetase (C) CTP synthetase (D) Orotidylic acid decarboxylase
Description : The activity of HMG-CoA reductase is inhibited by (A) A fungal inhibitor mevastatin (B) Probucol (C) Nicotinic acid (D) Clofibrate
Description : The bright-flash ERG: a. comes only from the cones b. is generated in a fully dark adapted eye by the highest intensity of light c. can be used to assess the overall retinal integrity in the presence of media opacity d. is abnormal in patients with age-related macular degeneration
Last Answer : can be used to assess the overall retinal integrity in the presence of media opacity
Description : Diastema is associated with (a) Presence of certain teeth (b) Organ of corti (c) Retinal cells (d) Absence of certain teeth
Last Answer : (d) Absence of certain teeth
Description : Provitamins A include (A) Retinal (B) Retionic acid (C) Carotenes (D) All of these
Description : A drug which prevents uric acid synthesis by inhibiting the enzyme Xanthine oxidase is (A) Aspirin (B) Allopurinal (C) Colchicine (D) Phenyl benzoate
Description : Maple syrup urine disease results from absence or serve deficiency of (A) Homogentisate oxidase (B) Phenylalanine hydroxylase (C) Branched chain amino acid transaminase (D) None of these
Description : All of the following statements about allopurinol are true except (A) It is a structural analogue of uric acid (B) It can prevent uric acid stones in the kidneys (C) It increases the urinary excretion of xanthine and hypoxanthine (D) It is a competitive inhibitor of xanthine oxidase
Description : In humans purine are catabolised to uric acid due to lack of the enzyme: (A) Urease (B) Uricase (C) Xanthine oxidase (D) Guanase
Description : An enzyme involved in catabolism of catecholamines is (A) Dopa decarboxylase (B) Aromatic amino acid decarboxylase (C) Monoamine oxidase (D) Catechol oxidas