関連ワード:  what does simple diffusion move    what does simple diffusion move across the cell membrane    what direction does simple diffusion move    what molecules does simple diffusion move    does simple diffusion move with or against the concentration gradient    does simple diffusion move from high to low concentration    does simple diffusion move down the concentration gradient    does simple diffusion move with the concentration gradient    does simple diffusion move molecules against a concentration gradient    does simple diffusion move water