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.
Interestingly, growth hormone must bind to two receptor molecules simultaneously to mediate its function. The hormone binds on the outside of the cell, bringing two receptors together. PDB entry 3hhr , shown here, includes the extracellular portion of two receptors bound to growth hormone.