1. Metabolism of Protein
Amino Acids

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

3. 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)

4. 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

5. 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.

6. 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.