1. Carbohydrates

2. Carbohydrates Small sugar molecules to large sugar molecules.
Carbo = carbon, hydrate = water
Examples:
A. monosaccharide
B. disaccharide
C. polysaccharide

3. Carbohydrates: Monosaccharide: the monomer of carbohydrates
one sugar unit
Examples: glucose (C6H12O6)
deoxyribose
ribose
Fructose
Galactose
glucose

4. Carbohydrates:
Glucose = blood sugar
All cells use glucose for energy

5. Carbohydrates: Monosaccharides
An OH (hydroxyl) group is attached to each carbon except one, which is double bonded to an oxygen (carbonyl).

6. Carbohydrates:
Classified according to the size of their carbon chains, varies from 3 to 7 carbons.
Triose = 3 carbons
Pentose = 5 carbons
Hexose = 6 carbons

7. Carbohydrates:

8. Carbohydrates: Disaccharide: a two-sugar unit
Made by joining together two monomers and removing a water molecule. What is the name of this process?
Examples:
Sucrose (glucose+fructose) – table sugar
Lactose (glucose+galactose) – milk sugar
Maltose (glucose+glucose) – seed sugar

9. Examples of Disaccharides:
Carbohydrates:
Examples of Disaccharides:
Oligosaccharides (“oligo-” means few or scant).
Several monosaccharides joined together.
Sucrose (table sugar) is disaccharide of one glucose and one fructose (Fig 3-1, p39).
Often combined with other molecules.
Many larger molecules have oligosaccharides attached for various purposes.
Sometimes used for cell ID.
The cell membrane has many proteins in it, some of which have attached oligosaccharides projecting away from the cell. Sometimes these are used as chemical labels for cell type.

10. Examples of Disaccharides:
Lactose = glucose + galactose
Sucrose = glucose + fructose

11. Carbohydrates
Polysaccharide: many sugar units. Structure: Polymers of a few hundred or a few thousand monosaccharides.
Examples: starch (bread, potatoes)
glycogen (beef muscle)
cellulose (lettuce, corn)
glucose
cellulose

14. Chitin

15. Carbohydrates: Functions
Store energy in chemical bonds
Starch is a storage form of energy found in plants.
Glycogen is a highly branched chain used by animals to store energy in muscles and the liver.

16. Carbohydrates: Functions
Structural component
Chitin is a polysaccharide used as a structural material in arthropod exoskeleton and fungal cell walls.
Cellulose is a fiber-like structural material - tough and insoluble - used in plant cell walls
Cell-cell communication