2. ©1993. Used by permission of Springer-Verlag. 1. Cells are fundamental units of life 2. Cells use chemical or solar energy to function and reproduce 3. Cells are macromolecular factories 4. Cells move, divide (mitosis), and sense environmental conditions

3. ©1993. Used by permission of Springer-Verlag. A prokaryotic cell

4. ©1993. Used by permission of Springer-Verlag.

5. A eukaryotic cell

6. (b) ©1980. Used by permission of Elsevier Science. Mitochondria are organelles that metabolize conversion of chemical energy from food into ATP.

7. Introduction to chromatin scales Electron micrograph of D.Melanogaster chromatin: arrays of regularly spaced nucleosomes, each ~80 A across.

8. Courtesy of Dr. Julian Heath.

9. ©1982. Used by permission of Jones and Bartlett Publishers, Sudbury MA.

10. Molecular composition of bacterial cells by weight Molecular composition of bacterial cells by weight: Small molecules 74% water 70% amino acids, sugars, fatty acids, ions 4% Macromolecules 26% proteins 15% RNA 6% DNA 1% lipids 2% polysaccharides 2%

12. ©1991 Larry Gonick.

13. ©1982, American Association for the Advancement of Science. Used by permission.

16. 20 types of amino acids in proteins

17. Protein 3D structure Protein Data Bank (PDB) http://www.rcsb.org

18. Protein Data Base accession code 1VII ({C.J. McKnight, D.S. Doering, P.T. Matsudaira, P.S. Kim, J. Mol. Biol. 260 126 (1996)).

19. Elastic rod model DNA looping induced by a Lac repressor tetramer

20. Protein Data Base accession code 1EHZ (H. Shi and P.B. Moore, RNA 6 1091 (2000)).

21. ©1993. Used by permission of Springer-Verlag.

22. Fatty acids Cellulose (polysaccharide)

23. A single peptide (protein building block) A polypeptide chain

24. A tyrosine (TYR) amino acid (one of 20 naturally occurring amino acids)

25. Peptide torsion angles and secondary structure omega = 180 deg, phi & psi are variable minimize E({phi,psi}) – protein folding problem

26. Secondary structure elements: alpha & 3-10 helices

27. Secondary structure elements: beta sheets

28. The Ramachandran plot

29. Turns of the polypeptide chain

30. Side chain conformations

31. Protein 3D structure (second look) Protein Data Bank (PDB) http://www.rcsb.org Protein functions: enzymes, gene regulation

32. DNA & RNA

33. The genetic code

34. Microtubules (25 nm): cytoskeleton Actin filaments (F-actin; 7 nm): actin cortex

36. Cell membranes are crowded: channels, receptors, pumps, actin cortex attachment points

39. ©1993. Used by permission of Springer-Verlag.