Proper functioning of Kreb cycle does not occur with deficiency of: (A) Thiamine, (B) Riboflavin, (C) Vitamin E, (D) Vit K
Answer is A. Biological active form is Thiamine pyrophosphate (TPP). Acts as a coenzyme in several metabolic reactions. * Acts as coenzyme to the enzyme pyruvate dehydrogenase complex (PDH) which conves pyruvic acid to acetyl-CoA (oxidative decarboxylation) Pyruvate PDH TPP Acetyl-CoA * Similarly acts as a coenzyme to a-oxoglutarate dehydrogenase complex and conves a-oxoglutarate to succinyl-CoA (oxidative decarboxylation). a-oxoglutarate dehydrogenase a-Oxoglutarate TPP Succinyl-CoARef: MN Chatterjea Textbook of Medical Biochemistry, 6th Edition, Page no: 178