Organic Compounds

1. Organic Compounds AP Biology

2. The Chemistry of Carbon

3. The Uniqueness and Variety of Carbon

7. Don’t forget the structure and function relationship. The shape of a molecule is important because structure often determines function (or, if you prefer, the shape probably evolved for a particular function). See page 41 in text.

8. Chemical Groups

9. Functional Groups; take place in the chemical reactions.

10. Smaller organic molecules join together to form larger molecules (macromolecules) • 4 major classes of macromolecules: • Carbohydrates • Lipids • Proteins • Nucleic acids Macromolecules

11. Long molecules built by linking a chain of repeating smaller units together • polymers • monomers = repeated small units • Held together by covalent bonds (shared pairs of electrons) Polymers

12. Condensation reaction • Dehydration synthesis • Joins monomers by “taking” H2O out • 1 monomer provides OH • the other monomer provides H • together these form H2O • requires energy & enzymes How to build a polymer

13. Hydrolysis • Use H2O to break apart monomers • Reverse of condensation reaction • H2O is split into H and OH • H & OH group attach where the covalent bond used to be • ex: Hydrolysis is used in digestion to break down large macromolecules How to break down a polymer

14. Carbohydrates

15. Carbohydrates are composed of C, H, O • carbo - hydr - ate CH2O (CH2O)x C6H12O6 • Function: • energy u energy storage • raw materials u structural materials Monomer: simple sugars (monosaccharides) • ex: sugars & starches

16. What functional groups? carbonyl aldehyde ketone hydroxyl

17. Most names for sugars end in -ose • Classified by number of carbons • 6C = hexose (glucose) • 5C = pentose (fructose, ribose) • 3C = triose (glyceraldehyde) Sugars

18. 5C & 6C sugars form rings in aqueous solutions (in cells). Sugar structure Notice carbons are numbered

19. C 6' C O 5' C C 4' 1' Numbered carbons C C 3' 2'

20. Monosaccharides • simple 1 monomer sugars • glucose • Disaccharides • 2 monomers • sucrose • Polysaccharides • large polymers • starch Simple & complex sugars

21. Disaccharide formed by dehydration synthesis. Two monosaccharides joined by a glycosidic linkage.

22. Dehydration synthesis disaccharide monosaccharides Building sugars | glucose | maltose | glucose glycosidic linkage

23. Dehydration synthesis monosaccharides disaccharide | glucose | fructose | sucrose structural isomers glycosidic linkage

24. Polymers of sugars • costs little energy to build • easily reversible = release energy • Function: • energy storage • starch (plants) • glycogen (animals) • building materials = structure • cellulose (plants) • chitin (arthropods & fungi) Polysaccharides

25. Branched vs linear polysaccharides

26. Molecular structure determines function Polysaccharide diversity • isomers of glucose • How does structure influence function???

27. Digesting starch vs. cellulose

28. Most abundant organic compound on Earth Cellulose

29. Which food will get into your blood more quickly? • apple • rice cakes • corn flakes • bagel • peanut M&M Glycemic index

30. Ranking of carbohydrates based on their immediate effect on blood glucose (blood sugar) levels • Carbohydrate foods that breakdown quickly during digestion have the highest glycemic indices. Their blood sugar response is fast & high. Glycemic index

31. Which food will get into your blood more quickly? • apple 36 • rice cakes 82 • corn flakes 84 • bagel 72 • peanut M&M 33 Glycemic index

32. Lipids

33. Lipids are composed of C, H, O • long hydrocarbon chain • Diverse group • fats • phospholipids • steroids • Do not form polymers • big molecules made of subunit smaller molecules • not a continuing chain

34. Structure: • glycerol (3C alcohol) + fatty acid • fatty acid = long HC “tail” with COOH group at “head” Fats dehydration synthesis

35. Triacylglycerol • 3 fatty acids linked to glycerol • ester linkage = between OH & COOH Fat

36. Dehydration synthesis

37. Long HC chain • polar or non-polar? • hydrophilic or hydrophobic? • Function: • energy storage • very rich • 2x carbohydrates • cushion organs • insulates body • think whale blubber! Fats

38. All C bonded to H • No C=C double bonds • long, straight chain • most animal fats • solid at room temp. • contributes to cardiovascular disease (atherosclerosis) = plaque deposits Saturated fats

39. C=C double bonds in the fatty acids • plant & fish fats • vegetable oils • liquid at room temperature • the kinks made by double bonded C prevent the molecules from packing tightlytogether Unsaturated fats

40. Structure: • glycerol + 2 fatty acids + PO4 • PO4 negatively charged • other small molecules may also be attached • adenine (ATP) Phospholipids

41. Hydrophobic or hydrophilic? • fatty acid tails = hydrophobic • PO4 = hydrophilic head • dual “personality” Phospholipids • interaction with H2O is complex • & very important!

42. Hydrophilic heads attracted to H2O • Hydrophobic tails “hide” from H2O • self-assemble into aggregates • micelle • liposome • early evolutionary stage of cell? Phospholipids in water

43. Phospholipids define outside vs. inside • Where do we find phospholipids in cells? • cell membranes Why is this important?

45. Phospholipids of cell membrane • double layer = bilayer • hydrophilic heads on outside • in contact with aqueous solution • hydrophobic tails on inside • form core • forms barrier between cell & external environment Phospholipids & cells

46. ex: cholesterol, sex hormones • 4 fused C rings • different steroids created by attaching different functional groups to rings cholesterol Steroids

47. Diversity in steroids

48. What a big difference a little atom can make! From Cholesterol  Sex Hormones

49. Important cell component • animal cell membranes • precursor of all other steroids • including vertebrate sex hormones • high levels in blood may contribute to cardiovascular disease Cholesterol

50. helps keep cell membranes fluid & flexible Cholesterol