How insulin works
Insulin acts like a key, opening body cells so that glucose can enter the cell to provide a source of energy.
Insulin is like the key to a car. A car needs fuel to run, but the key provides the spark that releases the fuel.
In your body, insulin is used to "spark" the use of glucose as fuel in your cells.
Normal body cell
Cell doors are open to allow insulin to bring glucose into the cells to use for energy.
Insulin resistant body cell
Cell doors are shut. The glucose cannot get into the body cells so they stay in the bloodstream.