So the liver can produce the ten non essential amino acids. And the liver can also use the 20 total amino acids to basically produce important types of proteins, such as, for example, albumin and fibrinogen. So albumin is the protein carrier of fatty acids in the blood plasma, while fibrinogen is an important type of enzyme, an important type of protein that is involved in the blood clotting cascade, as we'll see in a future lecture. Now, finally, in terms of the protein metabolism, liver cells can also convert ammonia in the blood into urea, which is then excreted by our kidneys. So when our glucose concentration in the blood runs low, when it is very low, what the liver cells can do is they can actually break down proteins into amino acids and they can use those amino acids to transform the amino acids into ATP molecules. In the process, we produce ammonia, which is a toxic substance.