Description : Histamine is formed from histidine by (A) Deamination (B) Dehydrogenation (C) Decarboxylation (D) Carboxylation
Last Answer : Answer : C
Description : Histidine is converted to histamine through the process of (A) Transamination (B) Decarboxylation (C) Oxidative deamination (D) Urea cycle
Last Answer : Answer : B
Description : Epinephrine is derived from norepinephrine by (A) Decarboxylation (B) Hydroxylation (C) Oxidation (D) N-methylation
Last Answer : Answer : D
Description : The sequential steps in the conversion of tyrosine to epinephrine are (A) Ring hydroxylation-decarboxylation-side chain hydroxylation-N-methylation (B) Side chain hydroxylation-decarboxylation- ... chain hydroxylation-N-methylation (D) N-methylation-decarboxylation-ring and side chain hydroxylation
Last Answer : Answer : A
Description : Biotin is involved in which of the following types of reactions? (A) Hydroxylation (B) Carboxylation (C) Decarboxylation (D) Deamination
Description : Vitamin B1 coenzyme (TPP) is involved in (A) Oxidative decarboxylation (B) Hydroxylation (C) Transamination (D) Carboxylation
Last Answer : (A) Oxidative decarboxylation
Description : d-UMP is converted to TMP by (A) Methylation (B) Decarboxylation (C) Reduction (D) Deamination
Description : Explain in brief about histamine It is formed by the decarboxylation of amino acid histidine ?
Last Answer : It accounts for 10% of granule weight. This histamine binds to specific receptors on various target cells.
Description : One of the main functions of Vitamin K is the cofactor for (A) Carboxylase for the formation of γ--carboxy glutamate (B) Methylation by S-adenosyl methionine (C) Carboxylation by biotin (D) One carbon transfer by tetra hydrofolate
Description : One of the main functions of Vitamin K is cofactor for (A) Carboxylate for the formation of γ carboxyglutamate (B) Methylation of δ-adenosyl methionine (C) Carboxylation of biotin (D) One carbon transfer by tetrahydrofolate
Description : Biotin is essential for (A) Translation (B) Carboxylation (C) Hydroxylation (D) Transamination
Description : The rate limiting step in the biosynthesis of catecholamines is (A) Decarboxylation of dihydroxyphenylalanine (B) Hydroxylation of phenylalanine (C) Hydroxylation of tyrosine (D) Oxidation of dopamine
Description : Which of the following amino acids produce a vasoconstrictor on decarboxylation? (A) Histidine (B) Tyrosine (C) Threonine (D) Arginine
Description : Which of the amino acid produces a vasodilator on decarboxylation? (A) Glutamin acid (B) Histidine (C) Ornithine (D) Cysteine
Description : A vasodilating compound is produced by the decarboxylation of the amino acid: (A) Arginine (B) Aspartic acid (C) Glutamine (D) Histidine
Description : The first reaction in photorespiration is: (a) Decarboxylation (b) Oxygenation (c) Carboxylation (d) Phosphorylation
Last Answer : Ans. ((b))
Description : Study the pathway given below. Atmospheric CO2 mesophyll cell Bundle sheath cell Plasma- desmata Plasma membrane Cell wall HCO Phosphoenol- 3 - pyruvate Cell wall C acid ... b) Fixation Transamination Regeneration (c) Fixation Decarboxylation Regeneration (d) Carboxylation Decarboxylation Reduction
Last Answer : (c) Fixation Decarboxylation Regeneration
Description : Histamine is formed from histidine by the enzyme histidine decarboxylase in the presence of (A) NAD (B) FMN (C) HS-CoA (D) B6-PO4
Description : UTP is converted to CTP by (A) Methylation (B) Isomerisation (C) Amination (D) Reduction
Description : Pyruvate is converted into acetyl-CoA by (A) Decarboxylation (B) Dehydrogenation (C) Oxidative decarboxylation (D) Oxidative deamination
Description : Biluveridin is converted to bilirubin by the process of (A) Oxidation (B) Reduction (C) Conjugation (D) Decarboxylation
Description : Conversion of a procarcinogen into a carcinogen often requires (A) Proteolysis (B) Microsomal hydroxylation (C) Exposure to ultraviolet radiation (D) Exposure to X-rays
Description : Newly synthesized tRNA undergoes posttranscriptional modifications which include all the following except (A) Reduction in size (B) Methylation of some bases (C) Formation of pseudouridine (D) Addition of C-C-A terminus at 5’ end
Description : Both folic acid and methyl cobalamin (vitamin B12) are required in (A) Deamination of serine (B) Deamination of threonine (C) Conversion of pyridoxal phosphate to pyridoxamine phosphate (D) Methylation of homocystein to methionine
Description : A coenzyme required in carboxylation reactions is (A) Lipoic acid (B) Coenzyme A (C) Biotin (D) All of these
Description : Carboxylation of acetyl-CoA to malonylCoA requires the enzyme: (A) Acetyl-CoA carboxylase (B) Pyruvate carboxylase (C) Acetyl transacylase (D) Acyl CoA-synthetase
Description : The vitamin required for carboxylation reaction is (A) Vitamin B2 (B) Vitamin B6 (C) Biotin (D) Vitamin B12
Description : A molecule of CO2 is captured by biotin when it acts as coenzyme for carboxylation reaction. The carboxyl group is covalently attached to (A) A nitrogen (N1) of the biotin molecule (B) Sulphur of thiophene ring (C) α-Amino group of lysine (D) α-Amino group of protein
Description : Pyridoxal phosphate is central to (A) Deamination (B) Amidation (C) Carboxylation (D) Transamination
Description : Vitamin K is a cofactor for (A) Gamma carboxylation of glutamic acid residue (B) β-Oxidation of fatty acid (C) Formation of γ-amino butyrate (D) Synthesis of tryptophan
Description : Carboxylation of acetyl—CoA to malonyl — CoA takes place in presence of (A) FAD+ (B) Biotin (C) NAD+ (D) NADP+
Description : An aneplerotic reaction which sustains the availability of oxaloacetate is the carboxylation of (A) Glutamate (B) Pyruvate (C) Citrate (D) Succinate
Last Answer : B
Description : In renal rickets, the following hydroxylation of Vitamin D3 does not take place: (A) 25 (B) 1 (C) 24 (D) 7
Description : Hydroxylation of 25-hydroxy cholecalciferol is promoted by (A) Cytochrome A (B) Panthyroid hormone (C) Cytochrome b (D) cAMP
Description : 25-hydroxylation of Vitamin D3 takes place in (A) Liver (B) Kidneys (C) Intestines (D) Pancreas
Description : 1-hydroxylation of 25-hydroxy Vitamin D3 takes place in (A) Liver (B) Kidneys (C) Intestine (D) Pancreas
Description : In retinal rickets, the following hydroxylation of Vitamin D3 does not take place: (A) 25 (B) 1 (C) 24 (D) 7
Description : Hydroxylation of 25-hydroxy cholecalciferol is promoted by (A) Cytochrome - a (B) Parathyroid hormone (C) Cytochrome-b (D) CAMP
Description : 25-hydroxylation of vitamin D3 takes place in (A) Liver (B) Kidneys (C) Intestine (D) Pancreas
Description : 1-hydroxylation of 25-OH vitamin D3 takes place in (A) Liver (B) Kidneys (C) Intestine (D) Pancreas
Description : 25-Hydroxylation of vitamin D occurs in (A) Skin (B) Liver (C) Kidneys (D) Intestinal mucosa
Description : Hydroxylation of Proline and Lysine in a protein is effected by (A) Vitamin B1 (B) Vitamin B2 (C) Vitamin B6 (D) Vitamin C
Description : The components of complement system are activated by (A) Microsomal hydroxylation (B) Phosphorylation (C) Glycosylation (D) Proteloysis
Description : Hydroxylation of phenylalanine requires all of the following except (A) Phenylalanine hydroxylase (B) Tetrahydrobiopterin (C) NADH (D) Molecular oxygen
Description : All of the following are required for hydroxylation of proline residues except (A) Ascorbic acid (B) Glutamate (C) Ferrous ions (D) Molecular oxygen
Description : All the following statement about hydroxyproline are true except (A) There is no codon for hydroxyproline (B) It is present in large amounts in collagen (C) Free proline cannot be hydroxylated to hydroxyproline (D) Hydroxylation of proline residues is catalysed by a dioxygenase
Description : In Ames’ assay, liver homogenate is included in the culture medium because (A) It converts pro-carcinogens into carcinogens (B) Liver can metabolise histidine (C) Salmonella mainly infects liver (D) Liver is very susceptible to cancer
Description : Malic enzyme convers malic acid, in the presence of NADP+ to Pyruvic acid. This reaction is a/an (A) Decarboxylation (B) Decarboxylation and Dehydrogenation (C) Dehydrogenation (D) Oxidation
Description : Decarboxylation of α-keto acids requires (A) Thiamine pyrophosphate, FAD, NAD+ (B) Flavin mononucleotide (C) NADP+ (D) NAD+ only