1. CARBOHYDRATES

2. Learning Outcomes:
B4 – analyse the structure and function of biological molecules in living systems - carbohydrates
Know formulas, chemical structure
List functions
Differentiate between monosaccharaides, disaccharides and polysaccharides
Compare structure of cellulose, starch and glycogen
Explain dehydration synthesis and hydrolysis

3. Elements
Carbohydrates contain C, H, and O in a ratio of approximately 1:2:1
2:1 ratio of H to O is the same is in H2O
Contain repetitions of H-C-OH

4. Monomers Monosaccharides (Simple carbohydrates, or sugars)
Common monosaccharides have 5 or 6 carbons, usually arranged in a ring

5. Hexoses are 6-carbon monosaccharides
Ex. Glucose, fructose, and galactose
All have the formula C6H12O6
Differ in arrangement of atoms
Draw glucose. See p.32 for other ways to draw.

6. 3 Ways to draw glucose

7. Another view:

8. Structural formula for glucose:
Each corner is a carbon atom

9. Pentoses are 5-Carbon monosaccharides
Ex. Ribose

10. Polymers Monosaccharides combine in chains to form polymers
Two monosaccharides combined = a disaccharide
Several monosaccharides combined = a polysaccharide

11. Disaccharides (2 monosaccharides) Ex. glucose + glucose  maltose
Glucose + fructose  sucrose
Glucose + galactose  lactose
Draw as on pagae 32

13. Sucralose …
Tastes like sugar, looks like sugar, but it’s not!

14. Polysaccharides (complex carbohydrates)
Long, branched or unbranched chains of monosaccharides (up to 4000!)
Common examples: starch, glycogen, cellulose
Differ in orientation of bonds and degree of branching

15. Starch
Draw as on page 33

16. Glycogen
Draw as on p 33

17. Cellulose
Draw as on p 33

18. Functions of Carbohydrates
Glucose and other monosaccharides are used in cellular respiration, to provide energy for cellular functions in all living organisms
Glycogen is used for energy storage in animals (found mainly in muscles and liver)

19. Starch is used for energy storage in plants (digested by animals to provide energy from food)

20. Cellulose provides structure in plant cell walls

21. Condensation Synthesis and Hydrolysis
Monosaccharides combine to form polymers by the process of condensation synthesis, or dehydration synthesis
A water molecule is given off for each bond that forms
Draw pictures on overhead step by step

22. One molecule of H2O is added for each bond that is broken
Polysaccharides are broken down into monosaccharides by the process of hydrolysis
One molecule of H2O is added for each bond that is broken
Draw pictures on overhead step by step