Based on the passage, what might have caused orcas to eat fewer sea lions and harbor seals?

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.

bradycardia ( blood presssure below 120/80mmhg )

it is contraindicated to give nitroglycerin to patients with blood pressure that is lower than normal range because the drug can cause blood pressure to drop further. it can lead to paradoxical bradycardia and less commonly, threatening hypotension.