1. Chapter 2: The Structure and Function of Macromolecules

2. Polymer Principles POLYMER: large molecule consisting of many identical or similar subunits connected together MONOMER: subunit or building block molecule of a polymer MACROMOLECULE: large organic polymer *Examples: carbohydrates, lipids, proteins, nucleic acids

3. POLYMERIZATION REACTIONS: chemical reactions that link 2 or more small molecules (monomers) to form larger molecules (polymers) DEHYDRATION SYNTHESIS REACTIONS (or CONDENSATION): reactions during which monomers are linked together; an –H and and –OH are removed, producing net removal of a water molecule for each covalent linkage

4. OHHO O H2OH2O Glucose C 6 H 12 O 6 Fructose C 6 H 12 O 6 Sucrose C 12 H 22 O 11 Water

5. HYDROLYSIS: process that breaks the covalent bonds between monomers by the addition of water molecules *Example: DIGESTION

6. O H2OH2O Sucrose C 12 H 22 O 11 Water OHHO Glucose C 6 H 12 O 6 Fructose C 6 H 12 O 6

9. Monosaccharides = single sugars are major nutrients for cells glucose is most common *examples: glucose, ribose, galactose, fructose

10. Disaccharides = double sugars Also a source of energy Formed when 2 monosaccharides combine in a dehydration reaction; Examples:  lactose (milk sugar): glucose + galactose  sucrose (table sugar): glucose + fructose

11. Polysaccharides = hundreds or thousands of monosaccharides formed by linking monomers in DEHYDRATION SYNTHESIS REACTIONS.

12. Disaccharide

13. Examples of energy storage polysaccharides: starch = glucose polymer in plants used for energy storage (in roots, tubers, etc.) glycogen = glucose polymer in animals stored in skeletal muscles and liver of humans & other vertebrates

15. Examples of structural support polysaccharides: cellulose = structural component of plant cell walls that cannot be digested by most organisms chitin = forms exoskeletons of arthropods

18. LIPIDS insoluble in water (because they are NONPOLAR, or HYDROPHOBIC) include: 1.Fats 2.Phospholipids 3.Steroids

19. 1. FATS Composed of:  A large proportion of C-H bonds and less oxygen than carbohydrates (the nonpolar C-H bonds make the chain hydrophobic and insoluble in water)  Example: C 57 H 110 O 6

20. during formation of a fat, dehydration synthesis reactions link fatty acids to glycerol

21. Fatty acids may vary in # of carbon atoms (usually even #)

22. Saturated vs. Unsaturated Fats SATURATED FATUNSATURATED FAT  no C-C double bonds in fatty acid tail  usually solid at room temp.  most animal fats  e.g., bacon grease, lard, butter  one or more C-C double bonds in fatty acid tail  usually a liquid at room temp.  most plant fats  e.g., corn, peanut, olive oils

24. Functions of Fats energy storage (1 g of fat stores 2x as much energy as 1 g of carbohydrate) cushions vital organs in mammals (e.g. kidney) insulates against heat loss (e.g. whales, seals)

25. 2. PHOSPHOLIPIDS Important component of cell membranes

26. 3. STEROIDS Important component of some hormones

27. Cholesterol … is used to make many other steroids (including sex hormones in vertebrates) common component of cell membranes can cause atherosclerosis (if have too much)