Unit 3 SCS #1, 3, 6, 13 (pg. 279)

1. a. One
    b. Two 
    c. Three
    d. 500 - 20,000 or more

3. Natural: starch, proteins, gelatin, nucleic acids
    Synthetic: fabrics, rubber, foam, adhesive

6. They are described as unsaturated because they contain carbon-carbon double bonds. 

13. I'm not sure.