Answer:
Oxaloacetate (4 carbon) joins with Acetyl CoA to yield Citrate (6 carbon)
Explanation:
Citrate synthase is an enzyme required during the first step of the citric acid cycle. This enzyme catalyzes the condensation of Acetate from Acetyl Coenzyme A (Acetyl CoA) and Oxaloacetate to yield Citrate, a six-carbon molecule, and Coenzyme A (CoA). Oxaloacetate is first condensed with acetyl CoA to produce citryl CoA which is subsequently hydrolyzed to CoA and citrate.