Which step constitutes the power stroke of muscle contraction?
A. ADP is released.
B. ATP is hydrolyzed, causing myosin to bind another actin subunit.
C. The phosphate ion is released, and the myosin head moves back to its original position.
D. ATP binds myosin, causing the myosin head to be released from actin
Answer: C. The phosphate ion is released, and the myosin head moves back to its original position.
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a. True b. False
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A) noncovalent interactions within the molecule B) addition of a phosphate group C) the length of the polypeptide chain D) the diverse side chains on the different amino acids E) the addition of sulfate groups to some amino acids