Question

6. At the motor end plate, ACh, triggers the influx of what ion into the sarcoplasm?

a. calcium

b. magnesium

c. potassium

d. bicarbonate

e. sodium

7. The myosin head acts as an enzyme that converts ADP and P into ATP.

a. True

b. False

8. During muscle fiber contraction

a. H-zones get bigger

b. I bands decrease in size

c. A bands get smaller

d. Z-lines move farther apart

e. zones of overlap get smaller

9. A motor unit is

a. one nerve and one fascicle

b. one motor neuron and one muscle fiber

c. one motor neuron and multiple muscle fibers

d. one motor neuron

e. one muscle fiber

10. If oxygen is readily available, ___________ is the most productive mechanism for generating ATP.

a. CP production

b. the Cori cycle

c. anaerobic respiration

d. glycolysis

e. aerobic respiration

Answer 1

6) At the motor end plate, ACh, triggers the influx of sodium ions into the sarcoplasm which generates a new action potential by changing the membrane potential of fiber.

7) The myosin head acts as an enzyme which converts ATP into ADP and P by breaking it down to gete energy for contraction. So , the above statement stating that it forms a new ATP molecule by binding ADP and P is false.

8) During muscle fiber contraction

H zones decreases in size , A band does not change its size , I band gets shortened , Z line move nearer , zones of overlap increase as fibers come nearer.

9) A motor unit is one motor neuron and multiple muscle fibers.

10) If oxygen is readily available , aerobic respiration is the most productive mechanism for generating ATP as the produced NADH and other molecules convert into ATP molecules in the presence of oxygen in electron transport pathway.