Amino Acids Structure carbon attached to carboxyl group + amino group + "R" group "R" group gives each of the 20 amino acids its unique properties only L-form amino acids (AA) are found in proteins Properties hydrophobicity allow for protein folding such that hydrophilic AAs face externally and hydrophobic AAs face internally hydrophobic AAs have aliphatic or aromatic R-groups hydrophilic AAs have oxygen or nitrogens in R-group pH acidic AAs are negatively charged at body pH login to view 1 more bullet basic AAs are positively charged at body pH login to view 1 more bullet essential/non-essential essential AAs must be part of the diet login to view 5 more bullets catabolic product glucogenic AAs can become glucose login to view 1 more bullet ketogenic AAs can become ketone bodies login to view 1 more bullet some AAs can become both ketone bodies or glucose login to view 1 more bullet Amino Acid Derivatives Tyrosine thyroid hormones (T3/T4) melanin deficiency login to view 13 more bullets catecholamines pathway see above Tryptophan NAD, NADP (niacin) serotonin Histidine histamine Arginine nitric oxide (NO) Glutamate GABA Glycine protoprophyrin → heme