2. Macromolecules Chapter 5

3. All are polymers Monomer – subunit of polymer Macromolecule – large organic polymer Those found in living systems: Carbohydrates Lipids Proteins Nucleic acids

4. MUST KNOW for each group Monomers Type of bond or linkage between monomers Examples – in living systems Functions – in living systems

5. Carbohydrates C, H, O Monomer= Monosaccharide (like glucose)

6. Lipids C, H, O Monomer = glycerol and fatty acids

7. Proteins C, H, O, N Monomer = Amino Acid

8. Nucleic Acid C, H, O, N, P Monomer = Nucleotide

9. Polymerization reactions Condensation (dehydration synthesis) –Monomers join covalently –Removal of water molecule –One monomer loses –0H –One loses –H –These join to form water –Requires energy and catalysts (enzymes)

10. Hydrolysis –Breaks covalent bond by addition of water –Digestive enzymes catalyze hydrolysis 40-50 common monomers (unity) Arranged in different ways (diversity )

11. Compare dehydration synthesis with hydrolysis

13. Carbohydrates Monomers – monosaccharide (usually multiples of CH 2 O like C 6 H 12 O 6 ) –Glucose, fructose, galactose –Glucose most common Stores energy in chemical bonds

14. Dihydroxyacetone Ribulose Ketoses Aldoses Fructose Glyceraldehyde Ribose Glucose Galactose Hexoses (C 6 H 12 O 6 ) Pentoses (C 5 H 10 O 5 ) Trioses (C 3 H 6 O 3 )

15. (a) Linear and ring forms(b) Abbreviated ring structure

16. Disaccharide double sugar (2 monosaccharides) Dehydration synthesis –> formula ? Glycosidic linkage formed-covalent bond forms by dehydration syn. Glucose + glucose = maltose Glucose + galactose = lactose Glucose + fructose = sucrose

17. Dehydration Synthesis (b) Dehydration reaction in the synthesis of sucrose GlucoseFructose Sucrose MaltoseGlucose (a) Dehydration reaction in the synthesis of maltose 1–4 glycosidic linkage 1–2 glycosidic linkage

18. Dehydration synthesis

19. Polysaccharides 100 to 1000 monosaccharides Functions: Storage polysaccharides: –Starch – plants Stored in plastids (amyloplast) –Amylose – simplest starch –Animals have enzymes to hydrolyze starch

20. Amylopectin

21. Glycogen – animal storage polysaccharide –Stored in muscles and liver of vertebrates –Provides energy to humans for about a day

22. Glycogen

23. Structural polysaccharides –Cellulose – plant cell wall Most abundant organic compound on Earth –Differs from starch in glycosidic linkage –Cannot be digested by most organisms –Exceptions-cows, termites have microorganisms that digest cellulose

24. Starch and cellulose-how are they different? Based on –OH attached to no. 1 carbon Starch = alpha configuration, often helical Cellulose = beta configuration, straight (glucose “upside down”)

25. Chitin – structural polysaccharide in animals Polymer of amino sugars (has a nitrogen group) Exoskeleton of arthropods (insects, spiders, crustaceans, etc.) Cell walls of some fungi Surgical thread

26. Lipids Hydrophobic Diverse group, not considered polymers 1. FATS –M–Monomers: one glycerol + 3 fatty acids Triglyceride or triacylglycerol –D–Dehydration synthesis (condensation) –E–Ester linkage –> 3 H 2 O molecules

27. Explain Ester linkage

28. Characteristics of fats Insoluble in water –b/c C-H bonds nonpolar Variation due to fatty acid composition –Vary in length –Vary in number and location of double bonds

29. Compare fatty acids

30. Compare saturated and unsaturated fats Double bonds ? At room temperature? Examples? Artificial hydrogenation –Converting unsaturated fatty acids to saturated by adding what? –peanut butter –Prevents lipids from separating out in liquid form

31. Function of fats Energy storage – 1g of fat stores twice as much energy as 1g polysaccharide –More compact fuel reservoir Cushions vital organs Insulates against heat loss

32. Phospholipid Monomers: one glycerol, 2 fatty acids, one phosphate group Phosphate negatively charged Fatty acid tail – hydrophobic Phosphate head – hydrophilic

33. Phospholipid

34. Phospholipid and self- assembly into bilayer

35. Functions Cell membranes –Form a bilayer Hydrophilic heads to exterior Hydrophobic tails to interior

36. Steroids Lipids with 4 fused carbon rings Cholesterol – important steroid –Precursor to sex hormones and bile acids –Component of cell membranes –Can contribute to atherosclerosis