Deamination occurs in the liver. Deamination is a process where an amino acid is broken down into a simpler molecule by removing its amino group (-NH2). This process is important because it helps to release nitrogen from amino acids, which can then be used to make other important compounds in the body, such as urea. The liver plays a key role in this process because it is responsible for removing excess nitrogen from the body, and deamination is one of the ways it accomplishes this.