AP Biology

1. AP Biology Biochemistry: Macromolecules Part 1

3. Organic Compounds • Four major groups: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids

4. Organic Compounds • Some organic compounds are small with one or a few functional groups- monomers. • Other organic compounds are made from linking several simple monomers together in complex chains- polymers.

5. Monomers  Polymers SimpleComplex • Monosaccharides  Polysaccharides • Glycerol, Fatty Acids Lipids, Fats • Amino Acids  Proteins • Nucleotides  Nucleic Acids

6. Macromolecules – “Macro” means “large” • Polymers “poly” means many; “mer” means unit. • These are formed from individual units called monomers “Building Blocks”. • Monomers are linked together by covalent bonds. Organisms need these to stay intact so the strongest type of bond is used.

7. Macromolecules are formed by Dehydration or Condensation Reactions. • Hydroxyl and Hydrogen must be aligned properly to produce water. • This orientation of molecules and making of a bond requires E. • Enzymeshelp speed up the rate of the reaction. • The –OH group from one monomer is removed and the –H from the other is removed – Dehydration Synthesis • H2O is removed which requires energy

8. Dehydration Synthesis HO H HO H HOH ENERGY HO H

10. Macromolecules are broken apart into individual monomers by Hydrolysis reaction. “lysis” means to split. • This process releases E in the bond breakage. • The processneeds water (hydroxyl and hydrogen) to fill the open bonds on the monomers. • Enzymes speed up the rate of the reaction here too.

12. Short polymer Unlinked monomer Dehydration removes a water molecule, forming a new bond Dehydration and HydrolysisReactions Longer polymer Dehydration reaction in the synthesis of a polymer Hydrolysis adds a water molecule, breaking a bond Hydrolysis of a polymer

13. Carbohydrates “Carbo” refers to Carbon; “hydrate” refers to water. • These macromolecules are mainly sugars. • Monosaccharides (Are the monomers or “building blocks”.) “sacch” means sugar. • Polysaccharides (Are the polymers.) • The chemical composition is: Carbon = Oxygen; 2X as much hydrogen is also present. • The names usually end with “ose”. Such as Fructose, Glucose, Sucrose.

14. CarbohydratesSee the Carbonyls and Hydroxides?

15. Dehydration reaction in the synthesis of maltose 1–4 glycosidic linkage Dehydration reactions in Carbohydrates Glucose Glucose Maltose Dehydration reaction in the synthesis of sucrose 1–2 glycosidic linkage Sucrose Fructose Glucose

18. These are primary E sourcesfor cells. • Carbohydrates serve as the raw building materials for the other 3 Organic Molecules. • The covalent bond between monomers is called a Glycosidic Linkage. It means “Sugar Bond”. • Carbohydrates can also be sources of stored E in cells or organisms. • Starch - E storage molecule in plants. • Glycogen – E storage molecule in Animals. • Cellulose – Structural component of plant cell walls. • Cellulose is the most abundant organic compound on Earth. • Chitin – This is the exoskeleton of some animals and also Fungi cell walls.

19. Carbohydrate Energy Storage

20. Insulin stimulates liver to take up glucose and store it as glycogen Glucagon stimulates liver to breakdown glycogen and release glucose into blood

22. Cellulose microfibrils in a plant cell wall Cell walls Microfibril Cellulose in Plant Cell Walls 0.5 µm Plant cells Cellulose molecules b Glucose monomer

23. Chitin

24. Polysaccharide?

25. Lipids • These macromolecules are fats, oils, waxes, and steroids. • Most lipids are hydrophobic molecules. “Hydro” means “water”; “phobic” means “fear of”. • Lipids are mainly composed of Hydrocarbons (All the Hydrogens means lipids have 2x The E of Carbs.)

26. Two Main parts • Fatty Acid (Hydrocarbon)(Number of Carbons will be a multiple of 2 if it is made by living cells) • 3 Carbon Glycerol molecule (alcohol) to hold the whole molecule together. • Lipids use a covalent bond called an Ester Linkage to hold the fatty acid and glycerol together. • An Ester linkage is a Carboxyl of the Fatty Acid paired with a hydroxyl of the glycerol molecule.

27. Ester Linkage and Lipids Fatty acid (palmitic acid) Glycerol Dehydration reaction in the synthesis of a fat

28. Ester linkage Triglycerol molecule

29. Fats A Fat = Glycerol + 1 or more Fatty Acids Glycerol- a 3 carbon alcohol. Fatty Acid- HO - C – R O Where R = hydrocarbon chain.

30. Hydrocarbon chain-16 carbons long Glycerol Dehydration synthesis

31. A Glycerol Three Fatty Acids

32. Major Types of lipids • Triglycerols or Triglycerides – your basic fat or oil • There are saturated fats. These fatty acids are saturated with hydrogen atoms. The molecule has no open bonds to put any more Hydrogen on. (These are solid at room temp.) (They usually are associated with animals.)These are the bad types of fat when it comes to our diet. • There are unsaturated fats. These have double or triple bonds that “could be broken”to add more Hydrogen to the fatty acid. (These are liquids at room temp.) (They usually are associated with plants, such as vegetable oil, sunflower oil, or peanut oil.)

34. Saturated vs. Unsaturated

36. There are also polyunsaturated fats. These have numerous double or triple bonds in the fatty acid portion. (These are also liquids at room temp.) (They are also usually from plants.)

37. So what is Peanut Butter? If it comes from a plant, it should be a(n)…. Unsaturated Fat! But it’s a solid! It is a hydrogenated fat!

38. Hydrogenated or Trans fats. These are oils turned solid by adding Hydrogen and by breaking the double or triple bonds so in order to TRANSFORM it into a saturated fat.

39. Phospholipids • These molecules replace a single fatty acid with a single Phosphate ion. (This part of the molecule is Hydrophilic. “philic” means “lover of”) (It loves water because the phosphate carries a negative charge. Remember water is polar, so the negative phosphate will be attracted to the positive hydrogen portion of water.) • They still have 2 Fatty Acid tails. (These are the Hydrophobic Portion of the molecule.) (They carry a neutral charge. Therefore are not attracted to water.) • Phospholipid Bi-layers (having 2 layers) are common for cell and organelle membranes.

40. Phospholipid of cell membranes

41. The structure of phospholipids: Results in a bilayer arrangement found in cell membranes. WATER Hydrophilic heads WATER Hydrophobic tails Figure 5.14

42. Cell Membranes

43. Waxes • These are made by combining alcohols with unsaturated oils. Such as girls lipsticks which also have coloring added to make the different shades.

44. Steroids, Hormones, and Cholesterol • A steroid has 4 carbon rings with the top ring looking like a house. • What make them different are the attached functional groups. These functional groups help determine the function of the steroid. • Cholesterol is also a steroid molecule, but it helps with cell membrane flexibility. All membranes need to have some cholesterol to remain flexible. Cholesterol IN EXCESS is bad for your health though.

45. Steroid Structure

46. Estradiol LE 4-9 Female lion Testosterone Male lion

48. Cell Membranes

49. Lipid Storage • Lipids are stored in adipose tissue in animals.