Key Answers

1. Carbon bonds with hydrogen, oxygen, phosphorus, sulfur, and nitrogen to form life's molecules.

2. Nucleic acids store and transmit genetic information.

3. Some proteins control cell processes and the rate of redactions. Others form important parts in cells, while others move substances into or out of cells or help to fight disease.

4. Lipids are used to store energy and are parts of membranes and waterproof coverings.

5. Carbohydrates provide energy and structural support for living things