-sheet

1. -sheet • 2 peptide backbones • Very open configuration • "Pleated" • Parallel and antiparallel

2. Tertiary Structure • Thermodynamically most stable form • Held together by • Hydrophobic interactions • Electrostatic interactions • -S-S- bonds • Can include non-protein groups • Prosthetic groups or co-enzymes • Determined by x-ray crystalography

3. Types of Tertiary Structures • Fibrous proteins • Silk • Keratin • Collagen • Globular proteins

7. Quaternary Structure

11. Carbohydrates (saccharides)

12. Monosaccharides • Polyhydroxy aldehydes or ketones • Aldoses—aldehyde on end • Ketoses—ketone in chain

13. Monosaccharides, con't. • Named by number of carbons • Trioses • Tetroses • Pentoses • Hexoses • Heptoses

14. Glucose • 4 chiral carbons • "D" configuration • Fischer projection

15. Ring formation

16. Chair configuration

17. Aldohexoses

18. Monosaccharide derivatives

19. Fructose

20. Glycosidic bonds

22. Polysaccharides

23. Types • Storage • Starch • Glycogen • Structural • Cellulose • Chitin • Extracellular matrix

24. Storage • Glucose in (14) linkages • Amylose—10-30% • unbranched • Amylopectin—70-90% • Branched every 12-25 residues • (16) linkages • Glycogen • Branched every 8-12 residues

27. Glycogen

28. Structural • Cellulose • Glucose • (14) linkages • No branches • Most abundant macromolecule

30. Structural, con't. • Chitin • N-acetyl glucosamine • Second most abundant macromolecule • Bacterial cell wall • peptidoglycan