1. ELEMENT ATOMIC # ATOMIC WEIGHT VALENCE ELECTRONS COVALENT BONDS H hydrogen11 C carbon612 N nitrogen714 O oxygen816 P phosphorus1531 S sulfur1632 1 4 5 6 5 6 1 4 3 2 3 2 SPONCH Facts

2. CHAPTER 2: THE CHEMICAL CONTEXT OF LIFE CONTEXT OF LIFE

3. The Hierarchy of Biological Order

4. Sodium Chlorine

5. sodium chloride- a compound

6. Magnesium deficiency

7. Goiter-enlarged thyroid gland due to an iodine deficiency

8. Helium

9. Biological Uses of Radioisotopes Tracers and Dyes Immunofluorescence Radiation treatments

10. PET scan-diagnosis

11. Radiation?

12. energy levels

13. * * *

14. Shapes of the orbitals is not important for biology but the shape of the molecule is often very important.

15. Diatomic nonpolar Two polar bonds produces a dipole Four polar bonds a nonpolar molecule??

16. Methane-a nonpolar molecule due to the orientation of the bonds

17. (+) H O (-) (-)

19. Ionic bonding

20. Salt Crystals

21. Nonpolar bonds H 2

22. Nonpolar Covalent Bond

23. Polar Covalent Bond

24. Ionic bond

25. Bonds are a continuum not discrete or separate Nonpolar  Polar  Ionic Differences in electronegativity and bonds formed

26. Electronegativity The attraction that an atom has for the electrons shared in a covalent bond When an electron moves from a molecule with lower electronegativity to a molecule with higher electronegativity, a small amount of energy is released. This is much less than a quantum and living systems are able to trap this energy in chemical bonds. –Electron Transport Chain –Photosynthesis –Cellular Respiration

27. Very polar becomes ionic

29. Shape is very important in Biology

30. Shape

31. a molecular mimic

32. Shape Unsaturated fatty acids have one or more double bonds between the carbons which makes them liquid at room temperature, they are derived form plants Saturated fatty acids have no double bonds between the carbons so all the carbons can rotate forming a straight molecule, they are derived from animal tissues and are solid at room temp.

33. How do double bonds different from single bonds? Do not bend as easy as single bonds Do not allow the molecules on either side of them to rotate

35. Mg atomic # is 12 valence is Cl atomic # is 17 valence is 2 7 So, they will form And the ratio will be MgCl 2 ionic bonds