1. Objectives: 1. Identify examples 2. Identify formulas 3. How are they put together or broken down? 4. Basic facts

2. - Quick, short-term energy. - Always have a 2:1 ratio of hydrogen to oxygen atoms. –Play a structural role when joined with other molecules. –C, H, O

3. Examples : Sugars Starches Cellulose

4. Simple Sugars: The simplest sugars are made of ONE molecule. They are called:

7. Fig. 5-3 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 )

9. Monosaccharides... These sugars have the same chemical formula, but different structural formulas…therefore they are

11. Two Monosaccharides... Two monosaccharides can join together to form a new sugar. This is now called a

13. Forming disaccharides... Notice, when forming a disaccharide, what molecule is formed once the sugars join?

16. Long term energy storage and structural purposes Consist of many glucose molecules linked together. The structure and function of a polysaccharide are determined by its sugar monomers and the positions of glycosidic linkages Only difference is the pattern: – Starch – Glycogen – Cellulose

17. Starch, a storage polysaccharide of plants, consists entirely of glucose monomers Plants store surplus starch as granules within chloroplasts and other plastids Glycogen is a storage polysaccharide in animals Humans and other vertebrates store glycogen mainly in liver and muscle cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

18. Fig. 5-6 (b) Glycogen: an animal polysaccharide Starch Glycogen Amylose Chloroplast (a) Starch: a plant polysaccharide Amylopectin Mitochondria Glycogen granules 0.5 µm 1 µm

21. The polysaccharide cellulose is a major component of the tough wall of plant cells Like starch, cellulose is a polymer of glucose, but the glycosidic linkages differ The difference is based on two ring forms for glucose: alpha (a) and beta (b)

23.  Glucose monomer Cellulose molecules Microfibril Cellulose microfibrils in a plant cell wall 0.5 µm 10 µm Cell walls

24. Enzymes that digest starch by hydrolyzing a linkages can’t hydrolyze b 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 Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

25. Fig. 5-9

26. Chitin, another structural polysaccharide, is found in the exoskeleton of arthropods Chitin also provides structural support for the cell walls of many fungi Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The structure of the chitin monomer. (a) (b) (c) Chitin forms the exoskeleton of arthropods. Chitin is used to make a strong and flexible surgical thread.

27. HOMEWORK: Assignment # 11 & 12 from your packet cover, reading and worksheets.