The Structure and Function of Macromolecules

1. The Structure and Function of Macromolecules

2. Macromolecules - larger molecules made from smaller ones. • 4 major classes of macromolecules: carbohydrates, lipids, proteins, and nucleic acids. • 3 of these are polymers because they are made from individual building blocks called monomers.

3. http://www.diabetes.org.nz/pics/carbohydrate_foods.jpg

4. Monomers - joined together through condensation or dehydration reaction (form macromolecules) • Requires energy; uses covalent bonds (links together monomers) • Water produced.

5. Water produced as by-product

6. Hydrolysis breaks polymers into monomers. • Water added to polymer; breaks bonds, creates monomers (i.e. digestive process in animals)

8. Carbohydrates • 1Carbohydrates - sugars (monomers) and polymers. • AMonosaccharides - simple sugars. • BDisaccharides - double sugars (monosaccharides linked together) • CPolysaccharides - polymers of monosaccharides. • Sugars named with –ose.

10. Monosaccharides needed for cellular work. • Help to synthesize other macromolecules.

12. Maltose - 2 glucose molecules. • Sucrose - 1 glucose, 1 fructose.

14. Polysaccharides - energy storage. • Starch - energy storage polysaccharide for plants. • Cellulose – polysaccharide; plant cell walls. • Animals store energy as glycogen.

17. Chitin - polysaccharide - makes up exoskeleton of arthropods (like crustaceans and our sowbugs!).

18. Chitin is used in surgery

19. Lipids • Lipids - no polymers (exception) • Lipids nonpolar (no affinity for water) • Fat made from glycerol and fatty acids.

21. Saturated fatty acid - No carbon-carbon double bonds in carbohydrate chain. (hydrogen at every possible position) • Form bad fats - solid at room temperature (butter, lard)

22. No double-double bonds

23. unsaturated fatty acid - 1+ carbon-carbon double bonds. • Formed by removal of hydrogen atoms from carbon skeleton. • Form good fats - liquid at room temperature (oils)

25. Purpose of fat - energy storage. • Gram of fat stores 2X as much energy as gram of polysaccharide. • Fat also cushions vital organs. • Layer of fat can also function as insulation.

26. http://www.healthline.com/blogs/diet_nutrition/uploaded_images/fat-cat-712938.jpghttp://www.healthline.com/blogs/diet_nutrition/uploaded_images/fat-cat-712938.jpg

27. MOST IMPORTANT LIPID IN BIOLOGY = Phospholipid • Phospholipids have 2 fatty acids attached to glycerol. • Fatty acid tails are hydrophobic, phosphate group and attachments form hydrophilic head.

29. When phospholipids added to water, self-assemble with hydrophobic tails pointing toward center, hydrophilic heads on outside. • Phospholipids in cell form bilayer; major component of cell membrane.

31. Hydrophilic Hydrophobic

32. Other Lipids • Steroids - lipids with carbon skeleton consisting of 4 fused carbon rings. • Cholesterol - component in animal cell membranes and hormones.

33. Cholesterol

34. Proteins • Proteins - support, storage, transport, defenses, and enzymes. • Made in ribosomes in cell. • Proteins - amino acids linked together to form polymer. • 20 different amino acids that can be linked together to form thousands of different proteins.

35. http://images.foodnetwork.com/webfood/images/gethealthy/nutritionalallstars/LeanProteins_header.jpghttp://images.foodnetwork.com/webfood/images/gethealthy/nutritionalallstars/LeanProteins_header.jpg

36. Amino acids link - polypeptides - combine to form proteins. • Amino acids made of hydrogen atom, carboxyl group, amino group, variable R group (or side chain). • R group makes amino acids different from one another.

38. Shape of protein determines function. • Shapes - 3 dimensional - determined by sequence of amino acids.

40. Primary structure of protein - linear sequence of amino acids determined by genetics.

43. Secondary structure - two shapes are usually formed: alpha coils or beta sheets.

45. Tertiary structure determined by interactions among R groups.

47. Quarternary structure - joining of 2+ polypeptide subunits. • Collagen and hemoglobin examples.

50. Protein’s shape can change due to environment. • pH, temperature, or salinity (salt concentrations) change - protein can denature (starts to fall apart) • Some proteins can return to functional shape after denaturation, others cannot.