1)Amino acids1. Chiral, only L-isomers exist in living world.2. Zwitterions; Functional groups give the diversity and versatility, 3. G is achiral; P has a cyclic alpha carbon; A, V, L, I, M (hydrophobic);

M, C (sulfur-containing); S, T, C, M, N, Q (polar); H, K, R (basic); D, E (acidic); F, Y, H, W (aromatic).

2)Protein structure and function1. Peptide bond: conformation, α-helix, β-sheet, random coil.2. Structure: 1˚, 2˚, 3˚ and 4˚; motif and domain. 3. Posttranslational modification4. Protein folding 5. Protein function

Lecture 3 Amino acids, peptides and proteins

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3.5 A

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Max Perutz (1914-2002)porin

Myoglobin