Question

carbon dioxide molecules cross the cell membrane by simple diffusion, while potassium ions cross by facilitated diffusion. complete the table to compare simple diffusion and facilitated diffusion.

Explanation:

Step1: Understand simple diffusion

Simple diffusion is a passive - transport process where small, non - polar molecules (like carbon dioxide) move down their concentration gradient directly through the phospholipid bilayer of the cell membrane without the need for energy or transport proteins.

Step2: Understand facilitated diffusion

Facilitated diffusion is also a passive - transport process. Molecules move down their concentration gradient, but large or charged molecules (like potassium ions) require the help of transport proteins (channel or carrier proteins) to cross the cell membrane. It also does not require cellular energy.

Answer:

	simple diffusion	facilitated diffusion
molecules pass directly through the phospholipids in the cell membrane	√
molecules pass through proteins in the cell membrane		√
large or charged molecules can move across the cell membrane		√
molecules move across the cell membrane without needing cellular energy	√	√