The Miller-Urey experiment was a chemical experiment that simulated the conditions thought at the time to be present on Earth's early atmosphere and tested the chemical origin of life under those conditions Steps taken to simulate Earth's early atmosphere are shown on the figure to the right What were the results of step 5? A)Results of step 5 produced prokaryotic organisms

B)After about a week, results demonstrated traces of amino acids and other organic compounds

C)Results of step 5 produced eukaryotic cells

D)Demonstrated that several inorganic compounds could be formed spontaneously

what subject is 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.