This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
In Maple syrup urine disease, which of the following compounds is accumulated: 
Select and explain. 
A. Homogentisic acid oxidase, B. Methyl malonyl CoA, C. a-keto acid decarboxylase, D. Transaminase
C: a-keto acid decarboxylase
Answer: C: a-keto acid decarboxylase 
Explanation: Ans. C. a-keto acid decarboxylaseValine, Leucine and Iso leucine are branched chain amino acids which undergo degradation to form various products. Valine is glucogenic and forms Succinyl CoA. Leucine is ketogenic and forms Acetoacetate and Acetyl CoA. Isoleucine is ketogenic (Acetyl CoA) and Glucogenic (Succinyl CoA). Absence of a-keto acid decarboxylase leads to an inherited disorder Maple Syrup Urine Disease. In this urine gives the smell of burnt sugar.