Actin-Myosin Muscle Contraction:

1
Actin-Myosin Muscle Contraction Seven Steps
1. myosin head relaxed note low-energy ADP
attached
2. myosin shaft bends attaches to actin
3. ADP breaks off
4. POWERSTROKE myosin head flexes. this
happens BECAUSE the ADP left. note this pulls
actin up to dotted line.
5. ATP (high energy) binds to actin
6. ATP breaks down into ADP myosin detaches from
actin (it is the ATP energy that causes the
detachment!)
7. actin resumes relaxed position (note actin
moves away from dotted line)