Check the items you included. came from Europe and Asia invCheck the items you included. came from Europe and Asia invaded the entire state of Wisconsin can burn your skin reproduces rapidly can be removed at root or with a powered brush cutter for large populationsaded the entire state of Wisconsin can burn your skin reproduces rapidly can be removed at root or with a powered brush cutter for large populations

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

the answer is: the „power stroke“ step.

muscle contraction can be divided into a few steps:

1. the release of ach (acetylcholine) in the synaptic cleft, binding of ach for its receptor and consequently opening of the ca channels.

2. the release of ca, binding of ca for the troponin

3. troponin shifting the tropomyosin, which was blocking the active site on the actin

4. myosin heads attaching to actin by breaking down atp to adp+ pi

5.   formation of the ‘cross-bridge’ on the active site of the actin filament by myosin head

6. “power stroke” -the cross bridge pulls actin, which slides over the myosin

9.     7. the release of adp completes the cross-bridge movement and atp attaches to myosin, breaking the actin-myosin cross bridge.