Amino acids are transported to the liver during digestion and most of the body’s protein is synthesised here.
If protein is in excess, amino acids can be converted into fat and stored in fat depots, or if required, made into glucose for energy by gluconeogenesis which has already been mentioned.
However, before amino acids can be utilized in these ways, the first step is to remove the nitrogen-containing group NH2. This very important metabolic process is called deamination.
In the hepatocytes, NH2 (the amino group) quickly changes into ammonia NH3, which is highly toxic to the body. The liver acts fast to convert ammonia into urea that then can be excreted in the urine and eliminated from the body.