1. Using water as an example, explain what a polar molecule is and discuss the nature of hydrogen bonding. What do hydrogen bonds have to do with water's resistance to temperature change?

2. HCl is a strong acid. What distinguishes a strong acid from a weak one? Briefly describe the pH scale. What would be the pH of a 0.1 Molar solution of HCl? What would be the concentration of OH- in this solution?

3. Define the terms hydrophilic and hydrophobic. What happens to nonpolar substances in water? What is the peculiar nature of soap molecules that enables them to interact with grease and water?

4. Draw the structure of a tripeptide with the amino acids glycine, phenylalanine and lysine (you do not need to have these memorized – look them up in your book). Place the lysine at the N-terminal and the phenylalanine at the C-terminal. What would be the net charge of this peptide in aqueous solution at neutral pH?

5. In a system of oil and water, where would you expect to find: sugar; octane; a short chain organic acid (e.g. acetic acid); an amino acid; a long-chain organic acid; a phospholipid?

6. What is a polysaccharide? What are the two principle ways that diversity among polysaccharides is created?

7. In which molecule of life would one look for sulfur? What purpose does it serve there?

8. What do all amino acids have in common? How do they differ?

9. Distinguish between a fatty acid, a phospholipid and a fat. How is it that the same number of carbons can be present in two different fats but one is a liquid at room temperature and the other a solid?