And the reason is the following. When we use acetyl coenzyme A and we feed it into the citric acid cycle, we actually use up a single oxalo acetate. So we use a single oxylacetate combined with acetytl coenzyme A, and we form citrates. And so ultimately, even though we do form oxalo acetate at the end, we use up one oxalo acetate at the beginning, and the net result is zero. So what that means is we cannot use acetylco enzyme A to help us form glucose in our liver. Now, let's focus on all these different amino acids.