Words about the concepts in this module can be obtained from the clues given.

Find these words in the block of letters:

1. Substance that reacts with excess stomach acid.
2. Common name for a substance that changes a physical or psychological function in the body.
3. Need of increasing amounts of a substance to experience the same initial effects.
4. Acetaminophen, ibuprofen, or acetylsalicylic acid, for example.
5. Benzoyl peroxide is the active antiseptic ingredient in ____ ointments.
6. These organic compounds are required in small amounts in the diet.
7. Stimulant in cola and coffee.
8. Birth control drugs belong to this class of organic compounds.
9. The amount of this drug is determined in the Breathalyzer test.
10. Anabolic steroids are synthetic derivatives of this natural compound.