Now, in step number one, we take our acetylcoenzyme A, and we mix it with a four carbon molecule known as oxaloacetate. So the oxalo acetate is a four carbon molecule that when we mix it with acetyl coenzyme A, we form a molecule known as citral coenzyme A, and then that citral coenzyme A reacts with an H 20 molecule to release the coenzyme A cofactor and to produce a six carbon citrate molecule. Now, the fact that this contains six carbons makes sense because our oxyloacetate contained four carbons, and the acetyl portion of the acetyl coenzyme contains two carbons. So when we combine these, we form the six carbon citrate molecule. Now, the question is, what exactly is the point of forming our citrate molecule? Well, basically, the reason we form a six carbon molecule is because this citric acid cycle involves two decarboxylation processes.