01. Amino Acids 1 Biomolecules • Protein • Carbohydrate • Nucleic acid • Lipid 2 peptide polypeptide protein di-, tri-, oligo- 3 4 fibrous proteins proteins globular proteins 5 Figure 4.1 Anatomy of an amino acid. Except for proline and its derivatives, all of the amino acids commonly found in proteins possess this type of structure. 6 Glycine (Gly, G) Alanine (Ala, A) Valine (Val, V)* Leucine (Leu, L)* Isoleucine (Ile. I)* 7 Serine (Ser, S) Threonine (Thr, T)* Cysteine (Cys, C) Methionine (Met, M)* cystine 8 Aspartate (Asp, D) Glutamate (Glu, E) Asparagine (Asn, N) Glutamine (Gln, Q) 9 Lysine (Lys, K)* 10 Arginine (Arg, R)*