A bodybuilder starts eating raw egg for protein. He used develop fatigue on moderate exercise. The doctor prescribes a vitamin. Which enzyme is deficient in him?
Ans. (b) Pyruvate CarboxylaseRef: Harpers Biochemistry 30th Ed; Page No- 560* Raw egg contains Avidin, it is antagonist of Biotin.* Eating raw egg is harmful because of Avidin present in raw egg inhibit biotin.* Affinity of Avidin to Biotin is stronger than most of the Antigen antibody reaction.* So doctor only prescribe Biotin.* ELISA test and Labeling of DNA test are used.* Why do u need biotin? Because biotin is the mother of all carboxylation reaction.* Only one carboxylase given in options, so option B will be the best answer.Note* Streptavidin is also biotin antagonist. It is purified from Streptomyces Avidin. Bind 4 molecule of biotin.Coenzyme role of BiotinBiotin dependent carboxylation reaction* Pyruvate carboxylase: pyruvate (3C)- oxaloacetate (4C)* Acetyl-CoA carboxylase: acetyl-CoA (2C)- malonyl-CoA (3C)* Propionyl-CoA carboxylase: propionyl-CoA(3C)- methylmalonyl-CoA(4C)* Methyl Crotonyl CoA Carboxylase.Biotin Independent carboxylation reaction* Malic enzyme (Pyruvate to Malate)* Carbamoyl phosphate Synthetases -I & II* Gamma Carboxylation (Vitamin K dependent)* Addition of CO2 tC6 in purine ring (AIR Carboxylase)Extra MileCoenzyme Role of Vitamin B complex Thiamine* Pyruvate dehydrogenase (links glycolysis to TCA cycle)* a-ketoglutarate dehydrogenase (TCA cycle)* Transketolase (HMP shunt)* Branched-chain ketoacid dehydrogenaseRiboflavin* Component of flavins FAD and FMN, used as cofactors in redox reactions, eg, the succinate dehydrogenase reaction in the TCA cycleNiacin* NAD+ linked Enzymes# Lactate dehydrogenase# Pyruvate dehydrogenase# a-ketoglutarate dehydrogenase# Isocitrate dehydrogenase# Malate dehydrogenase# Glutamate dehydrogenase# Glyceraldehyde 3 phosphate dehydrogenase* NADPH generating reaction# Glucose 6 phosphate dehydrogenase in HMP shunt pathway# 6 phospho Gluconate Dehydrogenase in HMP shunt pathway# Malic enzyme (NADP Malate Dehydrogenase)
Glucose 6 Phosphatase
Pyruvate Carboxylase
PEPCK
Glycogen Phosphorylase
Carbohydrates