How to write an essay answer:

1. read the question--if there is more than one part to the question, underline and number the parts
"name" requires you to write the name of something
"list" requires you to write a list of all required items or steps in a process
"explain" requires you to provide an explanation in your own words
"how?" requires you to describe a process or mechanism or a series of cause- effect events*
2. make a list of the main points for the answer to each part of the question
3. diagram the relationships between the main points (if that can be done)
4. use the list of main points and/or the diagram to write the answer

example:

step 1. the question only has one part, "explain the crossbridge cycle" (explain means that you need to do it in your own words)

step 2. list of main points:

1st - attachment
requires exposed binding sites
2nd - power stroke
release of ADP and P from previous cycle
3rd - detachment
ATP attaches to myosin
4th - recocking/energy transfer
ATP hydrolyzed, energy released

step 3.

step 4. the answer:

The first step in the crossbridge cycle is that attachment of myosin crossbridges (or heads) to exposed binding sites on actin (due to previous action of Ca, troponin and tropomyosin). The second step is the power stroke, in which the myosin heads bend inward and pull the thin filaments toward the center of the sarcomere. this makes the sarcomere shorten. the power stroke is accompanied by the release of ADP and P form the previous cycle. the third step is the detachment of myosin heads from actin. This occurs when ATP binds to the myosin crossbridge. the fourth step is energy transfer, in which the hydrolysis of ATP provides energy to cock the myosin head into position for the next cycle. The cycle continues as long as the binding sites are exposed and ATP is available.