Absence of phenylalanine hydroxylase causes (A) Neonatal tyrosinemia (B) Phenylketonuria (C) Primary hyperoxaluria (D) Albinism

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Answer :

Answer : D

Related questions

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

Last Answer : Answer : C

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

Last Answer : Answer : C

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

Description : Tyrosine hydroxylase is inhibited by (A) Catecholamines (B) α−Methyldopa (C) Phenylalanine (D) Vanillyl mandelic acid

Last Answer : Answer : A

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

Last Answer : Answer : B

Description : For Catecholamine biosynthesis the rate limiting enzyme is (A) DOPA decarboxylase (B) DOPAMINE β-hydroxylase (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase

Last Answer : Answer : C

Description : Richner-Hanhart syndrome is due to defect in (A) Tyrosinase (B) Phenylalanine hydroxylase (C) Hepatic tyrosine transaminase (D) Fumarylacetoacetate hydrolase

Last Answer : Answer : B

Description : Hydroxylation of phenylalanine requires all of the following except (A) Phenylalanine hydroxylase (B) Tetrahydrobiopterin (C) NADH (D) Molecular oxygen

Last Answer : Answer : C

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

Last Answer : Answer : D

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

Last Answer : Answer : C

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

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

Last Answer : Answer : D

Description : Niacin deficiency can occur in (A) Hartnup disease (B) Phenylketonuria (C) Alkaptonuria (D) None of these

Last Answer : Answer : A

Description : Increased urinary indole acetic acid is diagnostic of (A) Maple syrup urine disease (B) Hartnup disease (C) Homocystinuia (D) Phenylketonuria

Last Answer : Answer : B

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

Last Answer : Answer : C

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

Last Answer : Answer : D

Description : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase

Last Answer : Answer : B

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

Last Answer : Answer : B

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

Last Answer : Answer : C

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

Last Answer : Answer : A

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

Last Answer : Answer : B

Description : Microsomal hydroxylase system contains a (A) Di-oxygenase (B) Mono-oxygenase (C) Both (A) and (B) (D) None of thse

Last Answer : Answer : B

Description : Selenium is a constituent of the enzyme: (A) Glutathione peroxidase (B) Homogentisate oxidase (C) Tyrosine hydroxylase (D) Phenylalanin hydroxylase

Last Answer : Answer : A

Description : The deficiency of copper decreases the activity of the enzyme: (A) Lysine oxidase (B) Lysine hydroxylase (C) Tyrosine oxidase (D) Proline hydroxylase

Last Answer : Answer : A

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

Last Answer : Answer : A

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

Last Answer : Answer : B

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

Last Answer : Answer : A

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

Last Answer : Answer : C

Description : The enzyme involved in essential pentosuria is (A) Reductase (B) Hydroxylase (C) Isomerase (D) Racemase

Last Answer : Answer : A

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

Last Answer : Answer : A

Description : Biotin is a coenzyme of the enzyme (A) Carboxylase (B) Hydroxylase (C) Decarboxylase (D) Deaminase

Last Answer : Answer : A

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 : Answer : A

Description : β-Carotene, precursor of vitamin A, is oxidatively cleaved by (A) β-Carotene dioxygenase (B) Oxygenase (C) Hydroxylase (D) Transferase

Last Answer : Answer : A

Description : ω-oxidation takes place by the hydroxylase in microsomes involving (A) Cytochrome b (B) Cytochrome c (C) Cytochrome p-4500(D) Cytochrome a3

Last Answer : Answer : C

Description : Alkaptonuria occurs due to deficiency of the enzyme: (A) Maleylacetoacetate isomerase (B) Homogentisate oxidase (C) p-Hydroxyphenylpyruvate hydroxylase (D) Fumarylacetoacetate hydrolase

Last Answer : Answer : B

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

Last Answer : Answer : D

Description : Tyrosinosis is due to defect in the enzyme: (A) Fumarylacetoacetate hydrolase (B) p-Hydroxyphenylpyruvate hydroxylase (C) Tyrosine transaminase (D) Tyrosine hydroxylase

Last Answer : Answer : A

Description : Conversion of tyrosine to dihydroxyphenylalanine is catalysed by tyrosine hydroxylase which requires (A) NAD (B) FAD (C) ATP (D) Tetrahydrobiopterin

Last Answer : Answer : D

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

Last Answer : Answer : A

Description : Gout is a metabolic disorder of catabolism of (A) Pyrimidine (B) Purine (C) Alanine (D) Phenylalanine

Last Answer : Answer : B

Description : Melatonin is synthesised from (A) Phenylalanine (B) Tyrosine (C) Tryptophan (D) None of these

Last Answer : Answer : C

Description : In the B chain of insulin molecule, the Nterminal amino acid is (A) Proline (B) Threonine (C) Phenylalanine (D) Lysine

Last Answer : Answer : C

Description : In A chain of the insulin molecule the Nterminal amino acid is (A) Glycine (B) Valine (C) Serine (D) Phenylalanine

Last Answer : Answer : A