1. Ch. 2: “Chemistry of Life”
Vocabulary Review

2. Matching
1. ion
c. atom or molecule that has lost or gained one or more electrons
2. atom
a. smallest unit of matter that cannot be broken down by chemical means
3. compound
b. a substance made of the joined atoms of two or more different elements
4. amino acids
g. building blocks of protein
5. covalent bond
f. chemical bond in which electrons are shared
6. ionic bond
h. attraction between oppositely charged ions
7. element
d. a substance made of only one type of atom
8. solution
e. one substance evenly distributed in another

3. Fill in the Blank
9. A(n) ___ is a substance on which an enzyme acts during a chemical reaction.
substrate
10. An organic compound with a ratio of one carbon atom to two hydrogen atoms to one oxygen atom is a(n) ___.
carbohydrate
11. Glucose is a(n) ___ that is a major source of energy in cells.
monosaccharide

4. Fill in the Blank
12. A(n) ___ is an organic compound that is not soluble in water.
lipid
13. A(n) ___ is a long chain of amino acids.
protein
14. Subunits of DNA and RNA are called ___ .
nucleotides
15. DNA is a(n) ___ that encodes protein sequences.
nucleic acid

5. Explain the Difference
16. acid, base
Acids are compounds that form hydrogen ions when dissolved in water.
Bases are compounds that reduce the concentration of hydrogen ions when dissolved in water.
17. cohesion, adhesion
Cohesion is an attraction between substances of the same kind.
Adhesion is an attraction between different substances.

6. Explain the Difference
18. enzyme, active site
An enzyme is a substance that speeds up chemical reactions.
An active site is the location on an enzyme that binds to a substrate.
19. energy, activation energy
Energy is the ability to move or change matter.
Activation energy is the energy needed to start a chemical reaction.

7. Explain the Difference
20. DNA, RNA
DNA is a nucleic acid that stores hereditary information used to make proteins.
RNA is a nucleic acid that is involved in protein synthesis.
21. ATP, carbohydrate
ATP is an organic molecule that acts as the main energy currency of cells.
Carbohydrates are organic molecules that act as a source of energy in cells.