This four-carbon molecule is a substrate of citrate synthase.
The sodium pump of K. aerogenes uses energy from the decarboxylation of this molecule. This metabolite binds to a sulfhydryl group of succinate dehydrogenase in order to inhibit it, making it the most potent inhibitor of that enzyme. This intermediate, along with 2-ketoglutarate and glutamate, is necessary for the efficient transportation of NADH from the cytosol into the mitochondria via the malate-aspartate shuttle. This molecule is present in gluconeogenesis but (*) not glycolysis, since it helps bypass the pyruvate kinase step. Pyruvate carboxylation and aspartate transamination are two ways of ensuring adequate concentrations of this metabolite, and both of those reactions are anaplerotic. This four-carbon molecule is a substrate of citrate synthase. For 10 points, name this molecule that combines with acetyl-CoA to begin the citric acid cycle.
The sodium pump of K. aerogenes uses energy from the decarboxylation of this molecule.
oxaloacetate [or: oxaloacetic acid]