The Chemistry Of Life

1. The Chemistry Of Life

2. I Elements and atoms • A. Elements: Group of like atoms • Ex: Fe, S, H, N, O • 90 naturally occurring elements; 25 are essential to living organisms • trace elements: very small amt in body; Fe & Cu

3. Elements Sodium stored in kerosene Carbon above Ar Al Ne Cl Ca

4. B. Atoms: smallest part of matter • 1. Structure: nucleus contains protons and neutrons Electron cloud:electrons

5. Subatomic particle • Proton + nucleus • Neutron neutral Onucleus • Electron negative - cloud 1 H 1.001 go

6. Location of atom parts

7. Electron energy levels: 1st-2 2nd-8 3rd-18 (Their goal is to be filled with e-; that would be 8 e-) Valence Electrons: outer ring -on PT, matches: family # (except He) -important b/c: determine ability to react; chemrxn

8. Look at specific areas: go

9. Octet Rule: 8 val e- • Metals lose e- • Nonmetals gain e-

10. C. Isotopes: same p+, different neutrons Some are radioactive Ex: C-14, U-239 *C-14 is radioactive and used in radioactive dating of fossils

11. ii. Interactions of matter • Such as chemical reaction- • Can’t identify beginning substance from ending • Reactants Products • A. Compounds- • Ex: H2O, NaCl, CO2

12. B. Bonding-creates new substances & compounds; between electrons • 1. Covalent: share e- • Ex: H2O , H2

14. 2. Ionic Bonds-transfer e- • Ex: NaCl Makes ions charged particle go

15. Before After

16. Bonding animation • http://www.tutorvista.com/content/chemistry/chemistry-i/chemical-bonding/covalent-bond-animation.php

17. In your body Chemical reactions are called Metabolism

18. water • C. Water and Its Importance • 1. Water can transport materials needed • Ex: in blood, cells, osmosis, diffusion

19. water • 2. Sometimes when atoms share electrons, they do not share equally • A. Oxygen wants e- more than H • B. Polar molecule: molecule with unequally charged ends; ex: water (rule: polar dissolves polar) • C. Hydrogen bond: attraction between H & O • Opposite charges • Weak bond; easily broken http://www.stolaf.edu/people/giannini/flashanimat/water/water.swf go

20. water The H’s are pulled strongly to the Oxygen creating a partial charge on the elements. go

21. Now, what happens when two or more POLAR MOLECULES come in contact with each other? Polar Covalent Bond Polar Covalent Bond Opposite charges will attract, and one water molecule will cling to another water molecule, and so on. go What bond does this create??

22. HYDROGEN BONDS! Because of the POLAR covalent bond between the O and the H of H2O, the water molecule has acquired slight charges on each end of the water molecule. Water Molecules Water Molecules The hydrogen bond forms between the slight negative charge on the oxygen end of one water molecule with the slight positive charge on the hydrogen end of a different water molecule. + + _ hydrogen bonds

23. Cool water facts • Universal solvent • Has a high specific heat (resists rapid changes in temperature) • Expands as it freezes • Liquid water is more dense than ice (most dense at 4oC) • Is a hydrogen bond which is very weak, so they break, bond and reform with great frequency go

24. Creates capillary action in roots of plants (adhesion-stick to other things) • Most important compound in living things • Easily attracts other polar molecules, ions and water molecules (cohesion) • Non-polar (like oil or grease) compounds are “hydrophobic” and are not easily dissolved

25. D. Acids and Bases: • A. Acids: any substance that forms H+ ionsin water Ex: HCl, vinegar, citrus fruits • B. Bases: any substance that forms OH- ions in water Ex: NaOH, ammonia, antacids go

26. Ph scale go

27. The pH (potential hydrogen) scale is a measurement of the concentration of ions in a solution

28. e. Life substances • A. Organic Compounds: with carbon (may have H, N, O) Carbon atoms have unique char: 1-They can form 4 equal bonds because they h they have 4 electrons in their outer energy level (4 lines around them= 8 val e-) C 2-They can bond with themselves to form: straight chains, rings, branches 3-They may form: C – C C=C C=C

29. Organic substances form: • B. Polymer: large molecule formed from smaller molecules (monomers); large A monomer is the small unit of blue and red

30. 1. Dehydration synthesis/Condensation Reaction: • Making a polymer by removing water (monomer) • This is a chem rxn • Creates a polymer

31. Condensation Reactions or Dehydration Synthesis • Enzymes remove –OH from one molecule, H from another, form bond between two molecules • Discarded atoms join to form water monomer m m p polymer p

32. 2. Hydrolysis-breaking up polymer by adding water (hydro = water -lysis = to split) • Breaking up polymer and it breaks up • This is a chemrxn • Happens in food digestion • Creates monomers

33. Hydrolysis • Breaks polymers into smaller units, called monomers • Enzymes split molecules into two or more parts • An –OH group and an H atom derived from water are attached at exposed sites p p polymer m monomer m

34. C. There are four major macromolecules (polymers): • Carbohydrates-energy, pasta, rice, taters • Lipids-inc energy source, fats, oils, wax • Proteins-growth, immunity, enzymes, increase rxn rates • Nucleic Acids-genetics, DNA/RNA