Now, glycolysis actually has another important function. It is not only used to produce ATP molecules, but it is also used to produce the building blocks of our cells. So molecules such as fatty acids and amino acids. And we, and we'll focus on that in a future lecture. So ultimately what I'd like to focus on in this lecture is skeleton muscle cells and how glycolysis in skeleton muscle cells is actually regulated. Well, what's the entire point of using glycolysis in skeleton muscle cells?