Chapter 5 The Structure & Function of Macromolecules

1. Chapter 5 The Structure & Function of Macromolecules Slide show modified from Kim Foglia @ http://www.explorebiology.com

2. 4 MAJOR MACROMOLECULES • Carbohydrates • Lipids • Proteins • Nucleic acids

3. POLYMERS Image by Riedell Large molecule made by linking smaller subunits together • Monomers (small subunits) • Covalent bonds

4. SEE ANANIMATION

5. SEE ANANIMATION

6. CARBOHYDRATES http://www.graphic-design.com/Type/sugar/index.html http://www.ifr.ac.uk/SPM/images/Starch%20products.jpg

7. MONOSACCHARIDESSimple sugar molecules Composed of C,H,O (CH2O)n 3-7 carbons Name often ends in –ose D-glyceraldehyde C3H6O3 C5H10O5 C6H12O6 http://www.cybercolloids.net/library/sugars/glyceraldehyde.gif http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.html http://217.60.75.10/llt/biokemi/images/galactose.jpg http://217.60.75.10/llt/biokemi/images/galactose.jpg http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.html

8. NUMBERING • Carbons are numbered • Carbon with carbonyl group is #1

9. Is it D or L ? • For sugars with more than one chiral center, the D or L designation refers to the asymmetric carbon farthest from the aldehyde or keto group. • D=”dextro” or DEXTROROTATORY Latin for right; L=Levo,or LEVOROTATORY.. Latin for “sinister or Left”. Indicates that the molecule will rotate polarized light of specific wavelength to right or left. • Most naturally occurring sugars are D isomers. (WHY?) • D & L sugars are mirror images with same name.

10. Pentoses and hexoses can cyclizein water See animation • Carbons can be numbered • Carbon with carbonyl group is #1

11. CARBOHYDRATES SUPPLY ENERGY Cells burn glucose and store the energy released as ATP Images from: http://www.miranda.com/library.en/Images/Pictures/girls-runners.jpg http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookCHEM2.html

12. Disaccharides • Use dehydration synthesis to join TWO sugar molecules • covalent bond between 2 monosaccharides = GLYCOSIDIC linkage EX: Sucrose (table sugar) • most common disaccharide http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/Bio%20101/Bio%20101%20Lectures/Biochemistry/bioche1.gif http://www.biotech.iastate.edu/lab_protocols/HSSB-TLC_images/sucrose.gif

13. DISACCHARIDES Glucose + Fructose → Sucrose + H20 Glucose + Glucose → Maltose + H20 Glucose + Galactose → Lactose + H20

14. POLYSACCHARIDES~ “many sugars” http://www.district87.org/biology87/apbio/biochem/Activity6_notes.pdf • Ex: STARCH • polymer of αlpha glucose • linked by α1-4 glycosidic linkages • Function: Energy storage in PLANTSMost animals have the enzymes to hydrolyze starch, too http://www.langara.bc.ca/biology/mario/Assets/Amylopectin.jpg

15. POLYSACCHARIDES~ “many sugars” TWO KINDS OF STARCH: amylose = unbranched starch amylopectin = branched starch http://www.langara.bc.ca/biology/mario/Assets/Amylopectin.jpg

16. POLYSACCHARIDES~ “many sugars” EX: GLYCOGEN alpha 1-4 glycosidic bonds like starchMore branched than amylopectin FUNCTION: Energy storage in ANIMALS Stored in liver and muscle tissue http://www.abcbodybuilding.com/magazine04/scientific.htm

17. POLYSACCHARIDES~ “many sugars” FUNCTION: Structural PLANTS ~ CELLULOSE Major component in cell walls Most abundant organic compound on Earthbeta (ß) 1-4 glycosidic linkages

18. Enzymes that digest starch by hydrolyzing alpha linkages can’t hydrolyze beta linkages in cellulose • Cellulose in human food passes through the digestive tract as insoluble fiber • Some microbes use enzymes to digest cellulose • Many herbivores, from cows to termites, have symbiotic relationships with these microbes

19. POLYSACCHARIDES FUNCTION: Structural EX: CHITIN Structural polysaccharide made from ß glucose with a NITROGEN containing group attached

20. Major component of: Exoskeletons in Arthropods Cell walls in Fungi Dissolvable surgical thread

25. FATTY ACIDS USED CAN : • Be same or different in one molecule • Vary in length • Vary in number/location of double bonds • Saturated (single bonds) vs. unsaturated fats (double bonds) Kink in chain wherever a cis double bondoccurs

26. FATS LONG HC chain • NON-POLAR • HYDROPHOBIC • FUNCTION: • Energy storagevery rich • 2X energy in carbos • Cushions organs • Insulates bodyThink whale blubber!

28. Lipids, II

29. Phospholipids HEAD (PHILIC) Glycerol Phosphate group-PO4- Negative charge TAILS (PHOBIC) 2 fatty acids instead of 3

31. SEE AMOVIE!

37. PROTEINS http://images.foodnetwork.com/webfood/images/gethealthy/nutritionalallstars/LeanProteins_header.jpg

38. PROTEINS ARE MADE FROM AMINO ACID SUBUITS • Structure • Central carbon • Amino group • Carboxyl group • R group (side chain) • Variable group • Confers unique chemical properties • polar (hydrophilic), nonpolar (hydrophobic), acid or base • Join via DEHYDRATION SYNTHESIS reactions

39. Each kind of amino acid has a different R group20 different amino acids are used by cells to make proteins (There are a few other aa’s, but rare) R GROUPS

40. See ananimation

41. POLYPEPTIDES • POLYMERS OF AMINO ACIDS ARE CALLED POLYPEPTIDES • DNA determines the amino acid sequence http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookCHEM2.html http://www.cherishedtimedesigns.com/images/BaliCharmBraceletGraduation500.jpg

42. A functional PROTEIN is not just the polypeptide chain. A PROTEIN consists of one or more polypeptide chains twisted, folded, and coiled into a unique molecular shape What determines the shape? SEE AN ANIMATION Image from:  http://www.tvdsb.on.ca/saunders/courses/online/SBI3C/Cells/Protein-Structure03.jpg

48. pH effects the charge and reactivity of amino acids

49. PROTEIN STRUCTURE & FUNCTION • Function depends on structure • 4 levels of organization • result in 3-D structure