Aliver cell requires energy to move vitamins from an area of low concentration, across the cell membrane, to an area of high concentration. the process used by the liver cell is called

Active transport

Explanation:

The movement of molecules agains the concentration gradient is called active transport. And it requires the cell to use energy because molecules will naturally tend to move in the opposite direction. In active transport the molecules are moved from the side of the membrane where they are less concentrated to where they are more concentrated.

✿   this landform has a high elevation and a high relief

✿   this landform is a mountain