AP BIOLOGY

Detailed explanation-1: -Deamination of amino acids is mainly done by liver (separation of amino group of amino acid and its conversion to ammonia). Preparation of urea from the amino acids is done by the liver. Liver converts ammonia (obtained from deamination) into urea through ornithine cycle.

Detailed explanation-2: -Most of the amino groups of the excess amino acids are converted into urea through the urea cycle, whereas their carbon skeletons are transformed into other intermediates, mostly glucose.

Detailed explanation-3: -Deamination of amino acids results in the production of ammonium (NH4+). Ammonium is an extremely toxic base and its accumulation in the body would quickly be fatal. However, the liver contains a system of carrier molecules and enzymes which quickly converts the ammonia (and carbon dioxide) into urea.

Detailed explanation-4: -In situations of excess protein intake, deamination is used to break down amino acids for energy. The amino group is removed from the amino acid and converted to ammonia. The rest of the amino acid is made up of mostly carbon and hydrogen, and is recycled or oxidized for energy.

Detailed explanation-5: -The amino acids take part in certain common reactions like transamination followed by deamination for the production of ammonia. The amino group of amino acids is utilized for the formation of urea which is an excretory product for protein metabolism.