Cells utilize oxygen, glucose, amino acids, and hormones, producing waste products such as carbon dioxide, cellular debris, metabolites, and ammonia.

“Once that stuff gets out into the cells, the cells are going to use it. They're going to use the oxygen. They're going to use the glucose. They're going to use the amino acids. They're going to use the hormones. And as a consequence, they are going to create some waste products. There's going to be carbon dioxide that's created. There's going to be cellular waste in the form of actual physical debris. There are going to be metabolites. There's going to be ammonia. Basically, a bunch of waste product is going to then get kicked out of those cells into what's called the "extracellular space."”