Description : Neonatal tyrosinemia is due to deficiency of the enzyme: (A) p-Hydroxyphenylpyruvate hydroxylase (B) Fumarylacetoacetate hydrolase (C) Phenylalanine hydroxylase (D) Tyrosine dehydrogenase
Last Answer : Answer : B
Description : Albinism is due to deficiency of the enzyme: (A) Phenylalanine hydroxylase (B) Tyrosinase (C) p-Hydroxyphenylpyruvic acid oxidase (D) Tyrosine dehydrogenase
Last Answer : Answer : C
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
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
Last Answer : Answer : D
Description : Neonatal tyrosinemia improves on administration of (A) Thiamin (B) Riboflavin (C) Pyridoxine (D) Ascorbic acid
Last Answer : Answer : A
Description : All the following statements about albinism are correct except (A) Tyrosine hydroxylase (tyrosinase) is absent or deficient in melanocytes (B) Skin is hypopigmented (C) It results in mental retardation (D) Eyes are hypopigmented
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
Description : Tyrosine hydroxylase is inhibited by (A) Catecholamines (B) α−Methyldopa (C) Phenylalanine (D) Vanillyl mandelic acid
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 : For Catecholamine biosynthesis the rate limiting enzyme is (A) DOPA decarboxylase (B) DOPAMINE β-hydroxylase (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase
Description : Richner-Hanhart syndrome is due to defect in (A) Tyrosinase (B) Phenylalanine hydroxylase (C) Hepatic tyrosine transaminase (D) Fumarylacetoacetate hydrolase
Description : Hydroxylation of phenylalanine requires all of the following except (A) Phenylalanine hydroxylase (B) Tetrahydrobiopterin (C) NADH (D) Molecular oxygen
Description : Which of the following has a known association with phenylketonuria? 1) Presentation in the second year of life with absence seizures. 2) The association of red hair and brown eyes. 3) Normal development. 4) Musty odour. 5) Response of some patients to piridoxine.
Last Answer : Answers-4 Phenylketonuria is a quarter as common as congenital hypothyroidism, with an incidence of 1:10,000 live births. It is due either to phenylalanine hydroxylase deficiency or problems ... Co-factor defects are treated with a diet low in phenylalanine and high in neurotransmitter precursors.
Description : In adrenogenital syndrome due to total absence of 21-hydroxylase in adrenal cortex, there is (A) Deficient secretion of glucocorticoids (B) Deficient secretion of mineralcorticoids (C) Excessive secretion of androgens (D) All of these
Description : Which of the following would be prescribed for acne? A. Actiq B. Actonel C. Accu-Check D. Accutane Ans: D 2. An absence of pigment in the skin is called A. acanthosis nigricans B. albinism C. melanism D. xanthoderma
Last Answer : Ans: B
Description : Ochronosis is an important finding of (A) Tyrosinemia (B) Tyrosinosis (C) Alkaptonuria (D) Richner Hanhart syndrome FATS AND FATTY ACID METABOLISM 77
Description : Complete absence of hypoxanthine guanine phospharibosyl transferase causes (A) Primary gout (B) Immunodeficiency (C) Uric acid stones (D) Lesh-Nyhan syndrome
Description : Neonatal hypoglycemia is seen in which conditions?
Last Answer : Glycogen storage disease, type I, galactosemia, fructose intolerance.
Description : Tricorrhexis nodosa is a characteristic finding of (A) Argininosuccinic aciduria (B) Citrullinemia (C) Phenylketonuria (D) Hyperargininemia
Description : Niacin deficiency can occur in (A) Hartnup disease (B) Phenylketonuria (C) Alkaptonuria (D) None of these
Description : Increased urinary indole acetic acid is diagnostic of (A) Maple syrup urine disease (B) Hartnup disease (C) Homocystinuia (D) Phenylketonuria
Description : Amount of phenylacetic acid excreted in the urine in phenylketonuria is (A) 100–200 mg/dL (B) 200–280 mg/dL (C) 290–550 mg/dL (D) 600–750 mg/dL
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 : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase
Description : In the synthetic pathway of epinephrine, disulfiram (antabuse) inhibits the enzyme: (A) Tyrosine hydroxylase (B) Dopamine β-hydroxylase (C) DOPA decarboxylase (D) N-methyl transferase
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
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 : A deficiency of copper effects the formation of normal collagen by reducing the activity of which of the following enzyme? (A) Prolyl hydroxylase (B) Lysyl oxidase (C) Lysyl hydroxylase (D) Glucosyl transferase
Description : Microsomal hydroxylase system contains a (A) Di-oxygenase (B) Mono-oxygenase (C) Both (A) and (B) (D) None of thse
Description : Selenium is a constituent of the enzyme: (A) Glutathione peroxidase (B) Homogentisate oxidase (C) Tyrosine hydroxylase (D) Phenylalanin hydroxylase
Description : The deficiency of copper decreases the activity of the enzyme: (A) Lysine oxidase (B) Lysine hydroxylase (C) Tyrosine oxidase (D) Proline hydroxylase
Description : In which of the following types of enzymes, water may be added to a C—C double bond without breaking the bond? (A) Hydrolase (B) Hydratase (C) Hydroxylase (D) Oxygenase
Description : In which of the following types of enzyme water may be added to a C—C double bond without breaking the bond? (A) Hydrolase (B) Hydratase (C) Hydroxylase (D) Esterase
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 : ω-oxidation is normally a very minor pathway and is brought by hydroxylase enzymes involving (A) Cytochrome a (B) Cytochrome b (C) Cytochrome c (D) Cytochrome p-450
Description : The enzyme involved in essential pentosuria is (A) Reductase (B) Hydroxylase (C) Isomerase (D) Racemase
Description : The enzyme which can add water to a carbon-carbon double bond or remove water to create a double bond without breaking the bond is (A) Hydratase (B) Hydroxylase (C) Hydrolase (D) Esterase
Description : Biotin is a coenzyme of the enzyme (A) Carboxylase (B) Hydroxylase (C) Decarboxylase (D) Deaminase
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 : β-Carotene, precursor of vitamin A, is oxidatively cleaved by (A) β-Carotene dioxygenase (B) Oxygenase (C) Hydroxylase (D) Transferase
Description : ω-oxidation takes place by the hydroxylase in microsomes involving (A) Cytochrome b (B) Cytochrome c (C) Cytochrome p-4500(D) Cytochrome a3
Description : Alkaptonuria occurs due to deficiency of the enzyme: (A) Maleylacetoacetate isomerase (B) Homogentisate oxidase (C) p-Hydroxyphenylpyruvate hydroxylase (D) Fumarylacetoacetate hydrolase
Description : An inborn error, maple syrup urine disease is due to deficiency of the enzyme: (A) Isovaleryl-CoAhydrogenase (B) Phenylalnine hydroxylase (C) Adenosyl transferase (D) α-Ketoacid decarboxylase
Description : Tyrosinosis is due to defect in the enzyme: (A) Fumarylacetoacetate hydrolase (B) p-Hydroxyphenylpyruvate hydroxylase (C) Tyrosine transaminase (D) Tyrosine hydroxylase
Description : Conversion of tyrosine to dihydroxyphenylalanine is catalysed by tyrosine hydroxylase which requires (A) NAD (B) FAD (C) ATP (D) Tetrahydrobiopterin
Description : Ehlers-Danlos syndrome characterized by hypermobile joints and skin abnormalities is due to (A) Abnormality in gene for procollagen (B) Deficiency of lysyl oxidase (C) Deficiency of prolyl hydroxylase (D) Deficiency of lysyl hydroxylase
Description : Gout is a metabolic disorder of catabolism of (A) Pyrimidine (B) Purine (C) Alanine (D) Phenylalanine
Description : Melatonin is synthesised from (A) Phenylalanine (B) Tyrosine (C) Tryptophan (D) None of these
Description : In the B chain of insulin molecule, the Nterminal amino acid is (A) Proline (B) Threonine (C) Phenylalanine (D) Lysine
Description : In A chain of the insulin molecule the Nterminal amino acid is (A) Glycine (B) Valine (C) Serine (D) Phenylalanine