This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: vitamins, Subject name: Biochemistry
[{'content': 'Enzyme-deficient in lactic acidosis caused by thiamine deficiency is? \nSelect and explain. \nA. Pyruvate dehydrogenase, B. Succinate thiokinase, C. Cis aconitase, D. Isocitrate dehydrogenase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: TPP is the coenzyme for oxidative decarboxylation of alpha-ketoglutaric acid.eg: pyruvate to acetyl CoAPolyneuritis: It is common in chronic alcoholics. Alcohol utilization needs large doses of thiamine. Alcohol inhibits intestinal absorption of thiamine, leading to thiamine deficiency. Polyneuritis may also be associated with pregnancy and old age. Such thiamine deficiency in alcoholism may cause impairment of conversion of pyruvate to acetyl CoA. This results in increased plasma concentration of pyruvate and lactate, leading to lactic acidosis.Ref: DM Vasudevan - Textbook of Biochemistry, 6th edition, page no: 392', 'role': 'assistant'}]