Name ________________________________________ Date ___________ Pd. _______
Unit 2: Biochemistry
Extra Credit Review
1. The chemicals of life are divided into what 2 groups? a. inorganic and organic b. fats and lipids c. proteins and water d. saturated and unsaturated
2. Water molecules are polar, with a. the oxygen side being slightly positive and the hydrogen side being slightly negative. b. the oxygen and hydrogen sides being slightly positive. c. the oxygen side being slightly negative and the hydrogen side being slightly positive. d. the oxygen and hydrogen sides being slightly negative.
3. Which of the following organic compounds is the main source of energy for living things? a. carbohydrates b. lipids c. proteins d. nucleic acids
4. Which statement describes inorganic compounds? a. Water is the only inorganic comound b. Inorganic compounds are the same as organic compounds c. Inorganic compounds are not found in living things. d. Inorganic compounds do not contain carbon-hydrogen bonds
5. Which of the following makes up a molecule of water? a. one atom of hydrogen and two atoms of oxygen b. one atom of hydrogen and one atom of oxygen c. one atom of sodium and one atom of chlorine d. two atoms of hydrogen and one atom of oxygen

7.
6. A student measured the time required for a protein sample to be completely digested in the presence of an enzyme under different pH levels. At which pH is the enzyme least active? a. 7.2 c. 6.8 b. 7.1
A monosaccharide is a a. carbohydrate. b. nucleic acid.
8. All are properties of metals except d. c. lipid. d. protein.
6.9 a. malleable b. brittle solids c. conductors of heat and electricity d. Luster
9. The most abundant compound in most living things is a. sodium chloride. b. water. c. carbon dioxide. d. sugar.
10. Which of the following terms describes a substance formed by the combination of two or more elements in definite proportions? a. enzyme b. nucleus c. isotope d. Compound
11. Which of the following is not one of the four major organic compounds? a. Carbohydrates b. Nucleic acids c. Electrolytes d. Lipids

12.
Plant cells were put into sucrose solutions, each of which had a different concentration.
Scientists then measured the rate at which the plant cells absorbed the sucrose at each of the concentrations. Their results are shown in the above graph. Which is the best conclusion that the scientists could draw based on their data? a. The rate of absorption of sucrose does not continue to increase with all concentrations of sucrose. b. As the concentration of sucrose decreases, the rate at which plant cells absorb sucrose always increases. c. As the concentration of sucrose increases, the rate at which plant cells absorb sucrose always increases. d. The rate of absorption of sucrose by plant cells is not affected by the concentration of sucrose
13. The enzymes that catalyze cellular reactions are macromolecules made of organic compounds composed of carbon, hydrogen, oxygen, nitrogen, sulfur. These types of macromolecules are known as — a. nucleic acids b. proteins c. carbohydrates d. Lipids
14. The space surrounding the nucleus of an atom contains a. ions. b. protons. c. d. neutrons.
Electrons
15. The building blocks of all matter are a. electrons b. compounds c. ions d. Atoms
16. Many plants have waxy coatings on some surfaces. This coating reduces water loss because it is not water-permeable. This waxy coating is which of the following types of organic molecule?

a. lipid b. carbohydrate c. nucleic acid d. protein
17. If an atom contains 8 protons and 8 neutrons, its atomic number is a. b.
12
23 c. d.
8
1
18. The nucleus is made of a. electrons and neutrons. b. protons and electrons. c. protons and neutrons. d. protons, neutrons, and electrons
19. A covalent bond is formed as the result of a. transferring electrons. b. transferring protons. c. sharing electrons. d. sharing protons.
20. Amino acid is to protein as a. fat is to lipid b. DNA is to RNA c. simple sugar is to starch d. sugar is to fat