INSULIN

• What does insulin make AVAILABLE for facilitated diffusion?


  makes glucose transporters available for facilitated diffusion
• What do skeletal and cardiac muscle CELLS contain?


  A channel protein called GLUT4
• what is GLUT4?


  A glucose transporter
• What happens when insulin levels too low?


  GLUT4 is stored in vesicles in the cytoplasm of cells
• What triggers movement of GLUT4?


  When insulin binds to receptors on the cell-surface membrane, it triggers the movement of GLUT4 to the membrane
• What happens when the movement of GLUT4 to the membrane is triggered?


  Glucose can then be transported into the cell through the GLUT4 protein by FACILIATED DIFFUSION