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1. When NADH donates its electrons to the electron transport chain, which of the following is true?
A) NADH is reduced to NAD+.
B) NADH is oxidized to NAD+.
C) NADH is reduced to NADH2.
D) NADH is oxidized to NADH2.
E) None of the above are true.

2. Which of the following explains why your muscles burn when you go running?
A) Your muscles are running out of food, so your muscles are being digested to get energy.
B) Your muscles have no oxygen, so they can't digest food and are starving.
C) Your muscles start doing fermentation and alcohol is accumulating in your muscles.
D) Your muscles start doing fermentation, and lactic acid is accumulating in your muscles.
E) Your muscles can't digest food, so the food is accumulating in your muscles.

3. How many ATP are produced in the electron-transport chain with the complete metabolism of one glucose?
a. 36
b. 28
c. 34
d. 32

4. During aerobic respiration carbon dioxide is produced:
A) during glycolysis or fermentation
B) as pyruvate is converted to acetyl-CoA and during the Kreb’s cycle
C) during glycolysis, Kreb’s cycle, and the electron transport chain
D) only during the electron transport chain

5. Every known living creature is able to carry out this energy-producing reaction:
A) photosynthesis
B) glycolysis
C) Kreb’s cycle
D) aerobic respiration

6. Which of the following is carried out by enzymes in the cytoplasm?
A) Electron transport chain
B) Glycolysis
C) Translation
D) Transcription
E) Krebs Cycle

7. A cell will recycle all of its ATP about once every
a. 20 seconds
b. 2 minutes
c. 20 minutes
d. 2 hours
e. 2 days

8. If an atom gains an electron in a chemical reaction, it is said that the atom:
a. has been oxidized
b. has been regulated
c. has been reduced
d. has been catalysed
e. has activated

9. When a cell needs energy for a reaction, it converts ATP into
a. protein
b. ADP
c. glucose
d. cholesterol
e. pyruvic acid

10. Sue is in great physical condition and enters her first marathon. In spite of much training she “hits the wall” at about mile 22. Suddenly her legs feel like lead and she is disoriented. What happened to her muscle cells to cause this sensation?
a. the blood has run out of glucose
b. the lactic acid has built up to a critical level
c. the mitochondria have become damaged from too much oxidation
d. the cells have run out of glycogen stores
e. the capillaries have ruptured and are bleeding into the muscle tissues

11. What would happen if RBC's were placed in a cup of water with a solute concentration of 4%?
a) water would leave the cells at the same speed it was entering the cells
b) water would enter the cells through osmosis until they lyse
c) the cell would crenate
d) nothing

12. If you receive 1 liter of 9% saline solution, what effect will this have on your red blood cells?
a. crenation
b. lysis
c. no effect
d. increased oxygen-carrying capacity
e. they will move faster

13. Oxygen carried in the blood enters the cells of your tissues by:
a. simple diffusion
b. facilitated diffusion
c. pinocytosis
d. endocytosis
e. osmosis

14. Channel proteins are involved in:
A) active transport of ions against their concentration gradient
B) simple diffusion
C) recognition of self and nonself
D) osmosis
E) facilitated diffusion

15. The movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and cell expenditure of energy is called:
A) facilitated diffusion
B) diffusion
C) active transport
D) osmosis
E) endocytosis

16. When a cell folds itself around an object and then pinches off the plasma membrane to bring the object inside of itself, this is called:
a. facilitated diffusion
b. exocytosis
c. endocytosis
d. ciliation
e. osmosis

17. Which of the following cells is responsible for myelin formation in the peripheral nervous system?
a. Astrocyte
b. Oligodendrocyte
c. Schwann cell
d. Microglial cell
e. Satellite cell

18. Long extensions off neuronal cell bodies that conduct impulses away from the cell are:
a. axons
b. dendrites
c. glial cells
d. sodium-potassium pumps
e. cilia

19. Cells that insulate and speed impulse conduction down neurons in the PNS are:
a. nodes of Ranvier
b. astrocytes
c. Schwann cells
d. oligodendrocytes

20. A nerve impulse is initiated when:
a. a reversal in the polarized state of the cell causes it to reach action potential
b. physical disruption of the cell membrane causes some of its contents, including ions, to leak out
c. the Schwann cells move into their new position
d. voltage-gated channels close

21. Acetylcholine is a neurotransmitter which forms an excitatory synapse in ____ muscle and an inhibitory synapse in _____ muscle.
a. smooth; skeletal
b. skeletal; cardiac
c. cardiac; skeletal
d. skeletal; smooth

22. Before an action potential begins, sodium ions have a greater concentration
A) outside the neuron's cell membrane.
B) inside the neuron's cell membrane.
C) neither; the sodium concentration is the same outside as inside the cell's membrane.