Unit 3 Set 2

1st step of muscle constaction

Motor neuron releases acetylcholine, calcium is released into the muscle fiber

2nd step of muscle contraction

calcium goes to actin

3rd step of muscle contraction

Calcium binds to troponin, tropomyosin moves out of the way.

4th step of muscle contraction

ATP binds to myosin, myosin head moves up and attaches to the binding site on actin

5th step of muscle contraction

Myosin pulls actin towards its M line

6th step of muscle contraction

Myosin head releases from the actin, myosin head is read to bind to another binding site on the actin, myosin keeps binding and pulling on actin until acting reaches the m line

7th step of muscle contraction

The muscle will now pull on the bone to move the bones across a joint. The muscle will do this until the neuron stops sending acetylcholine to the muscle. This makes it relax.