Once insulin is released, it flows in the blood stream and facilitated entry of glucose into cells.  I like to think about it as  going in through the window in order to open up the locked door for glucose to enter.  It does this through a hexose transporter.

Without insulin present, glucose has no way of entry in to the cell.  As in the B-cells, glucose is brought in the cell by a very special and specific transporter.  The specialized transporter here is called a GLUT4 transporter (whereas the initial transporter for insulin release on B-cells is the GLUT2 transporter).  These transporters are found in adipose tissue and skeletal and cardiac striated muscle tissue.

For uptake of glucose to happen, insulin must bind to its receptor.  When the insulin molecule is bound, a signal transduction cascade activating the internal portion of the receptor and in turn sending a signal to the GLUT4 transporter to open up and let the glucose flow in.

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