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.
Several regulatory sequences in the promoter region of the human insulin gene bind to transcription factors. In general, the A-boxes bind to Pdx1 factors, E-boxes bind to NeuroD, C-boxes bind to MafA, and cAMP response elements to CREB. There are also silencers that inhibit transcription.