Question

chapter 2 basic chemistry 23
biochemistry: the composition of living matter

1. use the key choices to identify the substances described in the following statements. insert the appropriate letter or corresponding term in the answer blanks.

key choices
a. acid(s) b. base(s) c. buffer d. salt(s)

1. 2. 3. substances that ionize in water; good electrolytes
2. proton (h+) acceptor
3. ionize in water to release hydrogen ions and a negative ion other than hydroxide (oh-)
4. ionize in water to release ions other than h+ and oh-
5. formed when an acid and a base are combined
6. substances such as lemon juice and vinegar
7. prevents rapid/large swings in ph
8. use the key choices to complete the following statements concerning the properties and biological importance of water.

key choices
a. 70% e. dehydration h. hydrolysis k. polarity
b. 90% f. heat capacity i. lubricants l. salts
c. covalent g. hydrogen j. peptide m. water
d. cushioning

1. the ability of water to maintain a relatively constant temperature and thus prevent sudden changes is because of its high
2. biochemical reactions in the body must occur in (2).
3. about (3) % of the volume of a living cell is water. water molecules are bonded to other water molecules because of the presence of (4) bonds. water, as h+ and oh- ions, is essential in biochemical reactions such as (5) and (6) reactions. because of its (7), water is an excellent solvent and forms the basis of mucus and other body (8).

4.
5.
6.
7.
8.

1. use an x to designate which of the following are inorganic compounds or substances.

carbon dioxide fats proteins h2o
oxygen kcl glucose dna

Explanation:

1. 1 - A; 2 - B; 3 - A, B; 4 - B; 5 - A; 6 - D; 7 - D; 8 - A; 9 - C.
2. 1 - F; 2 - M; 3 - A; 4 - G; 5 - H; 6 - E; 7 - K; 8 - I.
3. Carbon dioxide - X; Fats - no X; Proteins - no X; H₂O - X; Oxygen - X; KCl - X; Glucose - no X; DNA - no X.

Answer:

1. 1. A
2. B
3. A, B
4. B
5. A
6. D
7. D
8. A
9. C
10. 1. F
11. M
12. A
13. G
14. H
15. E
16. K
17. I
18. Carbon dioxide, H₂O, Oxygen, KCl have X; Fats, Proteins, Glucose, DNA have no X.