Respuesta :

agianst a concentration gradient so the second one

Answer:

  • In facilitated diffusion, molecules move down their concentration gradient.

Explanation:

In facilitated diffusion, substances move into or out of cells down their concentration gradient through protein channels in the cell membrane. Simple diffusion and facilitated diffusion are similar in that both involve movement down the concentration gradient.

Osmosis refers specifically to the movement of water across a semipermeable membrane, with the solvent (water, for example) moving from an area of low solute (dissolved material) concentration to an area of high solute concentration.

Active transport is the movement of dissolved molecules into or out of a cell through the cell membrane, from a region of lower concentration to a region of higher concentration. The particles move against the concentration gradient , using energy released during respiration .