Lipid metabolism Q&A

Which of the pathways is hampered by the ABSENCE of oxaloacetate in the mitochondrion of the cell?    A.) malonyl-CoA formation        B.) acyl-CoA transportation       C.) glycolysis

The correct answer is malonyl-CoA formation (A). Oxaloacetate needs to react with acetyl-CoA to form citrate, which can move out of the mitochondrion and re-form acetyl-CoA. Without extramitochondrial acetyl-CoA, malonyl-CoA cannot be formed, and the subsequent steps of fatty acid synthesis will not occur. Acyl-CoA transportation (B) is wrong because it happens even before acetyl-CoA formation and carnitine, not oxaloacetate, is required for that process. Glycolysis (C) is completely wrong because it has nothing to do with lipid metabolism.