Metabolism of Protein Amino Acids

Protein Structure: Made up of a combination of about 20 naturally occurring amino acids Joined by Peptide Bonds Carboxyllic acid and an amino group

Role of the Liver: Amino Acids stored in liver, blood stream and body tissues Amino Acids can be transferred from one of these locations to another Amino acids are stored by deamination so that they can be used as an energy source (ATP)

Amino Acids as a Fuel Source Amino acids are only used as a fuel source during starvation When there is an abundance of amino acids they are converted into glucose (gluconeogenesis) and fatty acids and glycerol (lipogenesis) Glycogenesis is also known as reverse glycolysis because it takes pyruvic acids formed from deamination and converts them into glucose

Waste Products of Protein Metabolism Deamination forms ammonia which is toxic The liver detoxifies ammonia by converting it into the less toxic, water soluble substance urea.

Hormones and Protein Metabolism Human growth hormone and insulin increase the uptake of amino acids and protein synthesis in muscle tissue. Thyroid hormones also regulate protein metabolism Androgens from the testes and the adrenal gland stimulate protein synthesis.