Concept #1: Sliding Filament Model

Practice: Which statement best describes the sliding filament model of a sarcomere contraction?

Concept #2: Actomyosin Cycle Leads to Muscle Contraction

Concept #3: Actomyosin Cycle

Practice: Fill-in the blanks with numbers (1-7) to put the events of the actomyosin cycle in order from beginning to end:

a) _____: Myosin releases Pi.

b) 1 : Myosin binds ATP.

c) _____: Myosin head bonds tightly to thin actin filament.

d) _____: Myosin power stroke occurs.

e) _____: Myosin-actin interaction is broken.

f) _____: Myosin head pivots to a high-energy state.

g) _____: Myosin hydrolyzes ATP to ADP and Pi.

Concept #4: Muscle Relaxation via Troponin & Tropomyosin Regulation

Practice: Muscle contraction is directly caused by:

Practice: Which of the following does not occur during a muscle contraction?

Practice: Which of the following is false concerning the sliding-filament model of muscle contraction?

Practice: Which of the following statements correctly describes the relationship between cytosolic [Ca2+] and the corresponding sarcomere response?