This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Which of the following conversions does not require Biotin as a cofactor? 
Select and explain. 
A. Gamma carboxylation of glutamate, B. Acetyl Co-A to Malonyl Co-A, C. Propionyl Co-A to methyl malonyl Co-A, D. Pyruvate to oxaloacetate
A: Gamma carboxylation of glutamate
Answer: A: Gamma carboxylation of glutamate 
Explanation: Ans: A. Gamma carboxylation of glutamate(Ref: Harrison 19/e p96e-5; Harper 30/e p550, 561)Gamma carboxylation of glutamate:Carried out by Gamma-glutamyl carboxylase.Gamma-glutamyl carboxylase:Vitamin-K dependent enzyme.Catalyzes post-translational modification of vitamin K-dependent proteins.Biotin:Transfers carbon dioxide in reactions like acetyl-CoA carboxylase, pyruvate carboxylase, propionyl-CoA carboxylase & methylcrotonyl-CoA carboxylase.Biotin functions to transfer carbon dioxide in reactionsPyruvate carboxylasePyruvate (3C) to oxaloacetate (4C) in gluconeogenesisdegAcetyl-CoA carboxylaseAcetyl-CoA (2C) to malonyl-CoA (3C) in lipid synthesis.Propionyl-CoA carboxylasePropionyl-Co A (3C) to methylmalonyl-CoA (4C) inMethylmalonyl CoA carboxyl Propionic acid synthesis in bacteriaMethylcrotonyl-CoA carboxylaseLeucine catabolism