The liver also begins the process of maintaining the proper amino acid concentration in the blood. Explain how this is achieved in the liver. Describe the process of deamination; what system must remove the end product of deamination from the blood?
During digestion, the blood of the intestinal villi also picks up amino acids and, thus, has a much higher concentration of these substances than normal blood. The liver removes many amino acids from the blood, temporarily storing them before releasing them to tissues for use in creating enzymes, hormones, or protoplasm. Yet the typical diet contains more amino acids than are needed by the body at any one time. Because the animal body cannot store excess amino acids, they are converted by the liver into glucose, glycogen, or fat. In converting the amino acids, the liver removes the amino group (- ), a group which is not present in either sugars or fats. This process is called deamination. Next, the liver converts the discarded amino groups into ammonia and, then, into the less toxic urea which the liver dumps into the blood stream. The excretory system must remove the urea from the blood to prevent too high a concentration of the waste from building up in the blood.
