First substrate of Kreb's cycle is:: (A) Pyruvate, (B) Glycine, (C) Citrate, (D) Acetyl CoA
Answer is A. First Substrate of TCA cycle Best answer--Oxaloacetate Second best--pyruvate (because it can form Oxaloacetate by enzyme pyruvate Carboxylase). If these not given, then go for acetyl CoA.