To act on target cells, insulin binds to a specialized protein that is located on the membrane of your target cells: the insulin receptor. When insulin binds to the receptor, it activates a cascade of signals within the cell (a process called signal transduction), which is essential for insulin to have an effect on its target tissues. Insulin increases the entry of glucose into cells and causes the number of certain proteins specialized in glucose transport to increase in the membrane of their target cells, such as adipocytes (adipose tissue cells) and skeletal muscle cells.
