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

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
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All of the following statements about primary gout are true except (A) Uric acid stones may be formed in kidneys (B) Arthritis of small joints occurs commonly (C) Urinary excretion of uric acid is decreased (D) It occurs predominantly in males

Description : All of the following statements about primary gout are true except (A) Uric acid stones may be formed in kidneys (B) Arthritis of small joints occurs commonly (C) Urinary excretion of uric acid is decreased (D) It occurs predominantly in males

Last Answer : Answer : C

Choose the correct statement about allopurinol: A. It is a purine antimetabolite with antineoplastic activity B. It is a competitive inhibitor of xanthine oxidase C. It is inactive itself, but its metabolite alloxanthine is a competitive inhibitor of xanthine oxidase D. Both allopurinol as well as its metabolite alloxanthine are noncompetitive inhibitors of xanthine oxidase

Description : Choose the correct statement about allopurinol: A. It is a purine antimetabolite with antineoplastic activity B. It is a competitive inhibitor of xanthine oxidase C. It is inactive itself ... D. Both allopurinol as well as its metabolite alloxanthine are noncompetitive inhibitors of xanthine oxidase

Last Answer : B. It is a competitive inhibitor of xanthine oxidase

Allopurinol lowers the plasma concentration of: A. Hypoxanthine B. Xanthine C. Uric acid D. All of the above

Description : Allopurinol lowers the plasma concentration of: A. Hypoxanthine B. Xanthine C. Uric acid D. All of the above

Last Answer : C. Uric acid

A drug which prevents uric acid synthesis by inhibiting the enzyme xanthine oxidase is (A) Aspirin (B) Allopurinol (C) Colchicine (D) Probenecid

Description : A drug which prevents uric acid synthesis by inhibiting the enzyme xanthine oxidase is (A) Aspirin (B) Allopurinol (C) Colchicine (D) Probenecid

Last Answer : B

A drug which prevents uric acid synthesis by inhibiting the enzyme xanthine oxidase is (A) Aspirin (B) Allopurinol (C) Colchicine (D) Probenecid

Description : A drug which prevents uric acid synthesis by inhibiting the enzyme xanthine oxidase is (A) Aspirin (B) Allopurinol (C) Colchicine (D) Probenecid

Last Answer : (B) Allopurinol

An alternate substrate for orotate phosphoribosyl transferase is (A) Allopurinol (B) Xanthine (C) Hypoxanthine (D) Adenine

Description : An alternate substrate for orotate phosphoribosyl transferase is (A) Allopurinol (B) Xanthine (C) Hypoxanthine (D) Adenine

Last Answer : Answer : D

Physostigmine is a competitive inhibitor of (A) Xanthine oxidase (B) Cholinesterase (C) Carbonic anhydrase (D) Monoamine oxidase

Description : Physostigmine is a competitive inhibitor of (A) Xanthine oxidase (B) Cholinesterase (C) Carbonic anhydrase (D) Monoamine oxidase

Last Answer : Answer : B

All of the following statements about uric acid are true except (A) It can be formed from allantoin (B) Formation of uric acid stones in kidneys can be decreased by alkalinisation of urine (C) Uric acid begins to dissociate at pH above 5.8 (D) It is present in plasma mainly as monosodium urate

Description : All of the following statements about uric acid are true except (A) It can be formed from allantoin (B) Formation of uric acid stones in kidneys can be decreased by alkalinisation of urine (C) Uric acid begins to dissociate at pH above 5.8 (D) It is present in plasma mainly as monosodium urate

Last Answer : Answer : A

The end product of purine catabolism in man is (A) Inosine (B) Hypoxanthine (C) Xanthine (D) Uric acid

Description : The end product of purine catabolism in man is (A) Inosine (B) Hypoxanthine (C) Xanthine (D) Uric acid

Last Answer : Answer : D

Lesch-Nyhan syndrome, the sex linked recessive disorder is due to the lack of the enzyme: (A) Hypoxanthine-guanine phosphoribosyl transferse (B) Xanthine oxidase (C) Adenine phosphoribosyl transferase (D) Adenosine deaminase

Description : Lesch-Nyhan syndrome, the sex linked recessive disorder is due to the lack of the enzyme: (A) Hypoxanthine-guanine phosphoribosyl transferse (B) Xanthine oxidase (C) Adenine phosphoribosyl transferase (D) Adenosine deaminase

Last Answer : Answer : A

A drug which prevents uric acid synthesis by inhibiting the enzyme Xanthine oxidase is (A) Aspirin (B) Allopurinal (C) Colchicine (D) Phenyl benzoate

Description : A drug which prevents uric acid synthesis by inhibiting the enzyme Xanthine oxidase is (A) Aspirin (B) Allopurinal (C) Colchicine (D) Phenyl benzoate

Last Answer : Answer : B

In humans purine are catabolised to uric acid due to lack of the enzyme: (A) Urease (B) Uricase (C) Xanthine oxidase (D) Guanase

Description : In humans purine are catabolised to uric acid due to lack of the enzyme: (A) Urease (B) Uricase (C) Xanthine oxidase (D) Guanase

Last Answer : Answer : B

Schardinger’s enzyme is (A) Lactate dehydrogenase (B) Xanthine dehydrogenase (C) Uric oxidase (D) L amino acid dehydrogenase

Description : Schardinger’s enzyme is (A) Lactate dehydrogenase (B) Xanthine dehydrogenase (C) Uric oxidase (D) L amino acid dehydrogenase

Last Answer : Answer : B

Complete absence of hypoxanthine guanine phospharibosyl transferase causes (A) Primary gout (B) Immunodeficiency (C) Uric acid stones (D) Lesh-Nyhan syndrome

Description : Complete absence of hypoxanthine guanine phospharibosyl transferase causes (A) Primary gout (B) Immunodeficiency (C) Uric acid stones (D) Lesh-Nyhan syndrome

Last Answer : Answer : D

Allopurinol is indicated in the following category of chronic gout patients: A. Over producers of uric acid B. Under excretors of uric acid C. Those with tophi and/or renal urate stones D. All of the above

Description : Allopurinol is indicated in the following category of chronic gout patients: A. Over producers of uric acid B. Under excretors of uric acid C. Those with tophi and/or renal urate stones D. All of the above

Last Answer : D. All of the above

All of the following statements about uric acid are true except (A) It is a catabolite of purines (B) It is excreted by the kidneys (C) It is undissociated at pH above 5.8 (D) It is less soluble than sodium urate

Description : All of the following statements about uric acid are true except (A) It is a catabolite of purines (B) It is excreted by the kidneys (C) It is undissociated at pH above 5.8 (D) It is less soluble than sodium urate

Last Answer : Answer : C

Iron is present in all the following except (A) Peroxidase (B) Xanthine oxidase (C) Aconitase (D) Fumarase

Description : Iron is present in all the following except (A) Peroxidase (B) Xanthine oxidase (C) Aconitase (D) Fumarase

Last Answer : Answer : D

All the following are true about phenylketonuria except (A) Deficiency of phenylalanine hydroxylase (B) Mental retardation (C) Increased urinary excretion of p-hydroxyphenyl pyruvic acid (D) Decrease serotonin formation

Description : All the following are true about phenylketonuria except (A) Deficiency of phenylalanine hydroxylase (B) Mental retardation (C) Increased urinary excretion of p-hydroxyphenyl pyruvic acid (D) Decrease serotonin formation

Last Answer : Answer : C

Nitrosamine can deaminate (A) Cytosine to form uracil (B) Adenine to form xanthine (C) Guanine to form hypoxanthine (D) All of these

Description : Nitrosamine can deaminate (A) Cytosine to form uracil (B) Adenine to form xanthine (C) Guanine to form hypoxanthine (D) All of these

Last Answer : Answer : A

The nitrogenous base present in the RNA molecule is (A) Thymine (B) Uracil (C) Xanthine (D) Hypoxanthine

Description : The nitrogenous base present in the RNA molecule is (A) Thymine (B) Uracil (C) Xanthine (D) Hypoxanthine

Last Answer : Answer : B

All the following statements about phenylketonuria are correct except (A) Phenylalanine cannot be converted into tyrosine (B) Urinary excretion of phenylpyruvate and phenyllactate is increased (C) It can be controlled by giving a lowphenylalanine diet (D) It leads to decreased synthesis of thyroid hormones, catecholamines and melanin

Description : All the following statements about phenylketonuria are correct except (A) Phenylalanine cannot be converted into tyrosine (B) Urinary excretion of phenylpyruvate and phenyllactate is increased (C) It ... diet (D) It leads to decreased synthesis of thyroid hormones, catecholamines and melanin

Last Answer : Answer : D

In humans, the principal metabolic product of pyrimidines is (A) Uric acid (B) Allantoin (C) Hypoxanthine (D) β-alanine

Description : In humans, the principal metabolic product of pyrimidines is (A) Uric acid (B) Allantoin (C) Hypoxanthine (D) β-alanine

Last Answer : Answer : D

In inherited deficiency of hypoxanthine guanine phosphoribosyl transferase (A) De novo synthesis of purine nucleotides is decreased (B) Salvage of purines is decreased (C) Salvage of purines is increased (D) Synthesis of uric acid is decreased

Description : In inherited deficiency of hypoxanthine guanine phosphoribosyl transferase (A) De novo synthesis of purine nucleotides is decreased (B) Salvage of purines is decreased (C) Salvage of purines is increased (D) Synthesis of uric acid is decreased

Last Answer : Answer : B

Which of the following statements are true of oxidants? A. In addition to their pathophysiologic roles in inflammation, injury, and infection, oxidants also have physiologic roles. B. Oxidants may be generated from activated neutrophils and during reperfusion following a period of ischemia. C. The deleterious effects of oxidants include lipid peroxidation and cell membrane damage, oxidative damage to DNA, and inhibition of adenosine triphosphate (ATP) synthesis. D. The mechanism of ischemia-reperfusion injury involved the catalytic production of superoxide anion (O 2•) by the enzyme xanthine oxidase.

Description : Which of the following statements are true of oxidants? A. In addition to their pathophysiologic roles in inflammation, injury, and infection, oxidants also have physiologic roles. B. Oxidants may ... involved the catalytic production of superoxide anion (O 2 ) by the enzyme xanthine oxidase.

Last Answer : Answer: ABCD DISCUSSION: Oxidants are reactive oxygen metabolites that have both physiologic and pathophysiologic roles. As potent oxidizing agents, oxidants are involved in cytochrome P ... leukocyte infiltration and activation, causing further tissue damage by the release of cytotoxic proteases

A molybdenum containing oxidase is (A) Cytochrome oxidase (B) Xanthine oxidase (C) Glucose oxidase (D) L-Amino acid oxidase

Description : A molybdenum containing oxidase is (A) Cytochrome oxidase (B) Xanthine oxidase (C) Glucose oxidase (D) L-Amino acid oxidase

Last Answer : Answer : B

All of the following can occur in LeschNyhan syndrome except (A) Gouty arthritis (B) Uric acid stones (C) Retarted growth (D) Self-mutiliating behaviour

Description : All of the following can occur in LeschNyhan syndrome except (A) Gouty arthritis (B) Uric acid stones (C) Retarted growth (D) Self-mutiliating behaviour

Last Answer : Answer : C

In reversible non-competitive enzyme activity inhibition (A) Inhibitor bears structural resemblance to substrate (B) Inhibitor lowers the maximum velocity attainable with a given amount of enzyme (C) Km is increased (D) Km is decreased

Description : In reversible non-competitive enzyme activity inhibition (A) Inhibitor bears structural resemblance to substrate (B) Inhibitor lowers the maximum velocity attainable with a given amount of enzyme (C) Km is increased (D) Km is decreased

Last Answer : Answer : B

The correct sequence of the reactions of catabolism of adenosine to uric acid is (A) Adenosine→hypoxanthine→xanthine→uric acid (B) Adenosine→xanthine→inosine→uric acid (C) Adenosine→inosine→hypoxanthine→ xanthine uric acid (D) Adenosine→xanthine→inosine→hypoxanthine uric acid

Description : The correct sequence of the reactions of catabolism of adenosine to uric acid is (A) Adenosine→hypoxanthine→xanthine→uric acid (B) Adenosine→xanthine→inosine→uric acid (C) Adenosine→inosine→hypoxanthine→ xanthine uric acid (D) Adenosine→xanthine→inosine→hypoxanthine uric acid

Last Answer : Answer : C

In humans end product of purine catabolism is (A) Uric acid (B) Urea (C) Allantoin (D) Xanthine

Description : In humans end product of purine catabolism is (A) Uric acid (B) Urea (C) Allantoin (D) Xanthine

Last Answer : Answer : A

Xanthuric acid is an abnormal metabolite of (A) Xanthine (B) Uric acid (C) Tyrosine (D) Tryptophan

Description : Xanthuric acid is an abnormal metabolite of (A) Xanthine (B) Uric acid (C) Tyrosine (D) Tryptophan

Last Answer : Answer : D

All the following statements about primary gout are true except (A) Its inheritance is X-linked recessive (B) It can be due to increased activity of PRPP synthetase (C) It can be due to increased activity of hypoxanthine guanine phosphoribosyl transferase (D) De novo synthesis of purines is increased in it

Description : All the following statements about primary gout are true except (A) Its inheritance is X-linked recessive (B) It can be due to increased activity of PRPP synthetase (C) It can be ... activity of hypoxanthine guanine phosphoribosyl transferase (D) De novo synthesis of purines is increased in it

Last Answer : Answer : C

Hypouricaemia can occur in (A) Xanthine oxidase deficiency (B) Psoriasis (C) Leukaemia (D) None of these

Description : Hypouricaemia can occur in (A) Xanthine oxidase deficiency (B) Psoriasis (C) Leukaemia (D) None of these

Last Answer : Answer : A

Mammals other than higher primates do not suffer from gout because they (A) Lack xanthine oxidase (B) Lack adenosine deaminase (C) Lack purine nucleoside phosphorylase (D) Possess uricase

Description : Mammals other than higher primates do not suffer from gout because they (A) Lack xanthine oxidase (B) Lack adenosine deaminase (C) Lack purine nucleoside phosphorylase (D) Possess uricase

Last Answer : Answer : D

Enzymic deficiency in β-aminoisobutyric aciduria is (A) Adenosine deaminase (B) Xanthine oxidase (C) Orotidylate decarboxylase (D) Transaminase

Description : Enzymic deficiency in β-aminoisobutyric aciduria is (A) Adenosine deaminase (B) Xanthine oxidase (C) Orotidylate decarboxylase (D) Transaminase

Last Answer : Answer : D

An autosomal recessive disorder, xanthinuria is due to deficiency of the enzymes: (A) Adenosine deaminase (B) Xanthine oxidase (C) HGPRTase (D) Transaminase

Description : An autosomal recessive disorder, xanthinuria is due to deficiency of the enzymes: (A) Adenosine deaminase (B) Xanthine oxidase (C) HGPRTase (D) Transaminase

Last Answer : Answer : B

Molybdenum is a cofactor for (A) Xanthine oxidase (B) Aldehyde oxidase (C) Sulphite oxidase (D) All of these

Description : Molybdenum is a cofactor for (A) Xanthine oxidase (B) Aldehyde oxidase (C) Sulphite oxidase (D) All of these

Last Answer : Answer : D

A copper containing oxidase is (A) Cytochrome oxidase (B) Flavin mononucleotide (C) Flavin adenine dinucleotide (D) Xanthine oxidase

Description : A copper containing oxidase is (A) Cytochrome oxidase (B) Flavin mononucleotide (C) Flavin adenine dinucleotide (D) Xanthine oxidase

Last Answer : Answer : A

An enzyme which uses hydrogen acceptor as substrate is (A) Xanthine oxidase (B) Aldehyde oxidase (C) Catalase (D) Tryptophan oxygenase

Description : An enzyme which uses hydrogen acceptor as substrate is (A) Xanthine oxidase (B) Aldehyde oxidase (C) Catalase (D) Tryptophan oxygenase

Last Answer : Answer : C

Insulin degradation of disulfide bond formation is effected by (A) Pyruvate dehydrogenase (B) Xylitol reductase (C) Gutathione reductase (D) Xanthine oxidase

Description : Insulin degradation of disulfide bond formation is effected by (A) Pyruvate dehydrogenase (B) Xylitol reductase (C) Gutathione reductase (D) Xanthine oxidase

Last Answer : Answer : C

All the following statements about serotonin are true except (A) It causes vasolidatation (B) It causes bronchoconstriction (C) It is metabolized by monoamine oxidase (D) Its metabolite is 5-hydroxyindole acetic acid

Description : All the following statements about serotonin are true except (A) It causes vasolidatation (B) It causes bronchoconstriction (C) It is metabolized by monoamine oxidase (D) Its metabolite is 5-hydroxyindole acetic acid

Last Answer : Answer : A

In case of wilson’s disease, the features include all of the following except (A) Progressive hepatic cirrhosis (B) Keyser Fleisher ring (C) Aminoaciduria (D) Urinary excretion of Cu is decreased

Description : In case of wilson’s disease, the features include all of the following except (A) Progressive hepatic cirrhosis (B) Keyser Fleisher ring (C) Aminoaciduria (D) Urinary excretion of Cu is decreased

Last Answer : Answer : D

A 35-year-old male presented with an attack of acute gout. He was treated with a 10 day course of naproxen. His blood uric acid level is high. What future line of treatment is most appropriate: A. No regular medication. Treat attacks of acute gout when they occur with naproxen. B. Regular long-term treatment with naproxen C. Regular long-term treatment with allopurinol D. Start with allopurinol + naproxen for 2 months followed by long-term allopurinol treatment

Description : A 35-year-old male presented with an attack of acute gout. He was treated with a 10 day course of naproxen. His blood uric acid level is high. What future line of treatment is ... treatment with allopurinol D. Start with allopurinol + naproxen for 2 months followed by long-term allopurinol treatment

Last Answer : D. Start with allopurinol + naproxen for 2 months followed by long-term allopurinol treatment

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 : 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

Last Answer : Answer : A

Choose the correct statement about paracetamol: A. It increases uric acid excretion B. It is the most common drug implicated in causing analgesic nephropathy C. In equianalgesic doses it is safer than aspirin D. It stimulates cellular metabolism

Description : Choose the correct statement about paracetamol: A. It increases uric acid excretion B. It is the most common drug implicated in causing analgesic nephropathy C. In equianalgesic doses it is safer than aspirin D. It stimulates cellular metabolism

Last Answer : C. In equianalgesic doses it is safer than aspirin

All the following statements regarding ketone bodies are true except (A) They may result from starvation (B) They are formed in kidneys (C) They include acetoacetic acid and acetone (D) They may be excreted in urine

Description : All the following statements regarding ketone bodies are true except (A) They may result from starvation (B) They are formed in kidneys (C) They include acetoacetic acid and acetone (D) They may be excreted in urine

Last Answer : Answer : B

The probable metabolic defect in gents is (A) A defect in excretion of uric acid by kidney (B) An overproduction of pyrimidines (C) An overproduction of uric acid (D) Rise in calcium leading to deposition of calcium urate

Description : The probable metabolic defect in gents is (A) A defect in excretion of uric acid by kidney (B) An overproduction of pyrimidines (C) An overproduction of uric acid (D) Rise in calcium leading to deposition of calcium urate

Last Answer : Answer : C

Daily uric acid excretion in adult men is (A) 2–6 mg (B) 20–40 mg (C) 150–250 mg (D) 40–600 mg

Description : Daily uric acid excretion in adult men is (A) 2–6 mg (B) 20–40 mg (C) 150–250 mg (D) 40–600 mg

Last Answer : Answer : D

A 73 year old male presented with an acute attack of gout in his left knee. What is the most likely underlying metabolic cause? 1) decreased renal excretion of uric acid 2) endogenous overproduction of uric acid 3) excessive dietary purine intake 4) lactic acidosis 5) starvation

Description : A 73 year old male presented with an acute attack of gout in his left knee. What is the most likely underlying metabolic cause? 1) decreased renal excretion of uric acid 2) endogenous overproduction of uric acid 3) excessive dietary purine intake 4) lactic acidosis 5) starvation

Last Answer : Answers-1 The aetiology of gout can broadly be divided into cases where there is underexcretion of urate via the kidney (90%) or endogenous overproduction of uric acid (10%) although in practical ... diuretic use. Excessive dietary intake of purines is unlikely to be the main cause in this case.

A competitive inhibitor of an enzyme (A) Increases Km without affecting Vmax (B) Decreases Km without affecting Vmax (C) Increases Vmax without affecting Km (D) Decreases both Vmax and Km

Description : A competitive inhibitor of an enzyme (A) Increases Km without affecting Vmax (B) Decreases Km without affecting Vmax (C) Increases Vmax without affecting Km (D) Decreases both Vmax and Km

Last Answer : Answer : A

In non competitive enzyme activity inhibition, inhibitor (A) Increases Km (B) Decreases Km (C) Does not effect Km (D) Increases Km

Description : In non competitive enzyme activity inhibition, inhibitor (A) Increases Km (B) Decreases Km (C) Does not effect Km (D) Increases Km

Last Answer : Answer : C