Sodium ions can move through the membrane into the cell by diffusion through channels, but require active transport to move out of the cell. Describe these methods of movement across the membrane and clearly describe why we observe these differences for sodium movement.

I just need help with the last part. "clearly describe why we observe these differences for sodium movement."

Question

Sodium ions can move through the membrane into the cell by diffusion through channels, but require active transport to move out of the cell. Describe these methods of movement across the membrane and clearly describe why we observe these differences for sodium movement. 

I just need help with the last part. "clearly describe why we observe these differences for sodium movement."

ookawaiioo · Answer

You will soon learn that sodium (Na) is more concentrated outside of the cell. Thus, the Na will diffuse down its concentration gradient; Na goes into the cell. The cell has Na/K pumps that require ATP (energy) to remove Na from the cell called active transport.

Active transport of Na will reestablish the concentration gradient of Na. 

If youre still confused, maybe this will help:
1) More sodium outside of the cell. Sodium will move into the cell by diffusion( From higher concentration to lower concentration)
2) The sodium moving into the cell will build up. To prevent build up, there are protein channels (Na/K pumps) use ATP (energy) to remove Na from the cell, aka Active transport.