Acetyl-CoA Labeled with ¹⁴C in Both of Its Acetate Carbon

Multiple Choice

Acetyl-CoA labeled with ¹⁴C in both of its acetate carbon atoms is incubated with unlabeled oxaloacetate and a crude tissue preparation capable of carrying out the reactions of the citric acid cycle. After one turn of the cycle, oxaloacetate would have ¹⁴C in:

A) all four carbon atoms.
B) no pattern that is predictable from the information provided.
C) none of its carbon atoms.
D) the keto carbon and one of the carboxyl carbons.
E) the two carboxyl carbons.