Make sure that your cuts are as accurate as possible. If you need to trim areas, you can simply run the knife along the edge. Hold the knife so that the blade bites slightly into the edge. This can be a tedious process so try to get it right the first time.
When insulin binds to the receptor, it is thought to cause a change in shape that is propagated inside the cell, activating the tyrosine kinases. The details are still a mystery and an area of active research.
Binding of hormone to receptor initiates a series of events which leads to generation of so-called second messengers within the cell (the hormone is the first messenger). The second messengers then trigger a series of molecular interactions that alter the physiologic state of the cell.