Chapter 9, Problem 16RQ

Figure 38.37 Which of the following statements about muscle contraction is true? The power stroke occurs when ATP is hydrolyzed to ADP and phosphate. The power stroke occurs when ADP and phosphate dissociate from the myosin head. The power stroke occurs when ADP and phosphate dissociate from the actin active site. The power stroke occurs when Ca2+ binds the calcium head.

How do actin and myosin interact in a sarcomere to bring about muscle contraction? What roles do ATP and calcium play?

Skeletal muscle contraction requires _________. a. calcium ions b. ATP c. arrival of a nerve impulse d. all of the above

You are training athletes for the 100-meter dash. They need muscles specialized for speed and strength, not endurance. What muscle characteristics would your training regimen aim to develop? How would you alter it to train a long-distance swimmer?