1. MACROMOLECULES

2. Four Types of Macromolecules 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids

3. Carbohydrates  commonly found in foods: sugars and starches  these compounds always contain carbon, hydrogen and oxygen in a 1:2:1 ratio or CH 2 O  provide short or longer term energy storage for living organisms  provide structural support

4. Types of Carbohydrates 1. Monosaccharides 2. Disaccharides 3. Polysaccharides

5. 1. Monosaccharides  simple sugar containing 3 to 7 carbons  examples: glucose, fructose, galactose (isomers – same chemical formula C 6 H 12 O 6 but different 3D structure  provides instant energy energy

6.  Monosaccharides become ring shaped when in the presence of water. ring

7. 2. Disaccharides  made up of two monosaccharides  common examples: glucose + glucose = maltose glucose + glucose = maltose glucose + galactose = lactose glucose + galactose = lactose glucose + fructose = sucrose glucose + fructose = sucrose

8. Disaccharides… cont’d  formed by a condensation reaction (dehydration synthesis)  for maltose – a link forms between carbon 1 on one glucose and carbon 4 of the other.  this creates a 1-4 glycosidic linkage  water is released

9. Sucrose contains a 1-2 glycosidic link.

10. Making & Breaking Carbohydrates Condensation (dehydration) synthesis Hydrolysis Two important biochemical reactions monosaccharide + disaccharide (di = two)

11. Carbohydrates – Complex (Polysaccharides) Starch Granules (purple) in Potato Cells Starch = energy storage in plants Main Function: quick and short-term energy storage Contain many units of glucose in long chains Examples: Starch, glycogen, cellulose

12. Starch  made up of amylose (straight chain glucose polymer) and amylopectin (branched glucose polymer).  large insoluble molecule found in specialized storage plant structures (tubers in potatoes, fruit of corn, wheat, rice…)  how plant stores extra glucose made during photosynthesis

13. Glycogen = energy storage in animals Glycogen (red) in Hepatocytes (liver cells) Glucose (monomer) Glycogen (polymer) Carbohydrates – Complex (Polysaccharides) liver muscle

14. Carbohydrates – Complex (Polysaccharides) Cellulose = polysaccharide found in plant cell walls Cellulose fibers Macrofibril Microfibril Chains of cellulose

15. Cellulose  straight chain glucose polymer  chains packed into bundles called microfibrils  provide support in cell wall  main structural component of plants Makes starch (can digest) Makes cellulose (can’t digest)

16. Chitin  exoskeleton of insects and crustaceans (provides protection)  straight chain glucose polymer with nitrogen group at carbon 2