Ch. 2: “Chemistry of Life”

Vocabulary Review

Matching

1. ionc. atom or molecule that has lost

or gained one or more electrons

2. atoma. smallest unit of matter that

cannot be broken down by chemical means

3. compoundb. a substance made of the joined

atoms of two or more different elements

4. amino acidsg. building blocks of protein

5. covalent bondf. chemical bond in which

electrons are shared6. ionic bondh. attraction between oppositely

charged ions7. elementd. a substance made of only one

type of atom8. solutione. one substance evenly

distributed in another

Fill in the Blank

9. A(n) ___ is a substance on which an enzyme acts during a chemical reaction.

• substrate10. An organic compound with a ratio of one

carbon atom to two hydrogen atoms to one oxygen atom is a(n) ___.

• carbohydrate11. Glucose is a(n) ___ that is a major source of

energy in cells.• monosaccharide

Fill in the Blank

12. A(n) ___ is an organic compound that is not soluble in water.

• lipid13. A(n) ___ is a long chain of amino acids.• protein14. Subunits of DNA and RNA are called ___ .• nucleotides15. DNA is a(n) ___ that encodes protein

sequences.• nucleic acid

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.

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.

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.