<prompt> Which of the following acts as a coenzyme in carboxylation reaction?RiboflavinNiacinBiotinPantothenic acid  <response>: Ans. C. Biotin. Ref Harpers Biochemistry 27thCh. 44.Vitamin B7 biotin:Function:-Cofactor for carboxylation enzymes which add a l-carbon group:- Pyruvate carboxylase: pyruvate 3Coxaloacetate 4C.- Acetyl-CoA carboxylase: acetyl-CoA 2Cmalonyl-CoA 3C.- Propionyl-CoA carboxylase: propionyl-CoA 3Cmethylmalonyl-CoA 4C.- 3 methylerotoyl CoA methyl glutaconyl CoADEFICIENCY: due to antibiotic overuse, ingestion of raw eggs avidin in egg white AVIDLY binds to biotin.Ch by Dermatitis, alopecia, enteritis.VitaminsVITAMINENZYMES IN WHICH IT ACTS AS COENZYMESDEFICIENCY DISEASE1. Vit. B1 Thiamine Pyruvate dehydrogenase complex Oxidation decarboxylation of a-keto-acid Transketolase reaction Tryptophan pyrolase Beri-Beri disease Werinicke encephalopathy2. Vit. B2 Riboflavin heart stable but light sensitive FMN and FAD are two coenzymes of this vit. Constituent of cytochrome -c- reductase Warburg-yellow enzyme Fumarate dehydroganase Cheilosis Glossitis Seborrheic3. Vit. B3 Niacin NAD and NADP are its active forms with operate as hydrogen and electron transfer agents They are co-enzymes for various types of dehydrogenase like- Alcohol dehyrogenase- Lactate dehydrogenase- Malate dehydrogenase- Pyruvate dehydrogenasePellagra CB 3 Ds:- Diarrhea- Dermatitis- Dementia4. Vit. B6 Pyridoxine In vit.B6 defi Kynureine levels rise, which is converted to xanthurneic acid - a reliable criteria for B6 defi Co-transaminase Co-decarboxylase Deaminase Involved in synthesis of Co-A Coenzyme for Kynureninase Epileptiform convulsion in infants Sideroblastic anemia It is used in Rx of oxalate stone of kidney and homocytinuria5. Pantothenic acid Active form is Co-A Formation of Acetyl CoA Formation of succinyl CoA Oxidation of F. acids Synthesis of F. acids G.I symptoms Changed sleep pattern Easy fatigue Burning foot syndrome6. Biotin Carboxylase enzyme carboxylation reaction Leiners disease Exfoliative dermatitis7. Vit. B12 Cyanocobalamine To convert-Methyl malonyl CoAHomocysteine methionineRibonucleotideDeoxyribounuleotideMethyl malonyluriaHomocystinuriaPernicious anemiaSACD 