Question

when glucose is in the bloodstream, insulin binds to cells. this signals the cell to move glucose transport proteins into the cell membrane. glucose then enters the cell using facilitated diffusion.
what happens to glucose in the bloodstream if insulin does not bind to the cell membrane?
o a glucose receives energy from atp, which allows the glucose to enter the cell.
o b glucose is unable to enter the cell, and the glucose remains in the bloodstream.
o c glucose moves from high concentration outside the cell to low concentration inside the cell.
o d. glucose can enter the cell by moving through the channel formed by the empty insulin receptor

Explanation:

When insulin binds to its receptor, it signals the cell to move glucose transport proteins into the cell membrane, allowing glucose to enter the cell via facilitated diffusion. Facilitated diffusion is a passive process (does not require ATP). Option A suggests glucose receives energy from ATP, which is incorrect as glucose entry here is via facilitated diffusion (passive). Option B is wrong because glucose can enter cells (when insulin - mediated transport proteins are present). Option C is incorrect as the movement is from high (bloodstream) to low (inside cell) concentration (facilitated diffusion). Option D is correct as glucose moves through channels (formed by transport proteins) from high (bloodstream) to low (inside cell) concentration.

Answer:

D. Glucose can enter the cell by moving through the channel formed by the empty insulin receptor.