April 3, 2006

Chapter 20 Amino Acids and Proteins

20.5 Protein Structure: Primary and Secondary Levels

Artifical Sweeteners: Relative Sweetness

Secondary Structure

Alpha Helix: H-bonding between N-H and C=O four amino acids apart on helix

Beta Pleated Sheet: side-by-side hydrogen bonding

Triple Helix- collagen: three polypetides braided together (tissue, blood vessels, skin, tendons, ligaments, cornea, cartilage)
20.6 Protein Structure: Tertiary and Quaternary Levels

Tertiary structure: R group interactions

Quaternary structure: intreactions between two or more polypeptide subunits

Hydrophobic

Hydrophilic

Salt bridges

Hydrogen bonds

Disulfide bonds

Quaternary structure hemoglobin: two a and two b chains: Heme

Homework:

20.3, 20.5, 20.7, 20.9, 20.13, 20.15, 20.17, 20.19, 20.21, 20.23, 20.25, 20.27, 20.29, 20.31, 20.37, 20.39, 20.43, 20.47