Question

which is not needed for facilitated diffusion? a atp b protein channels c concentration gradient which can move easily across the membrane without facilitated diffusion? a polar molecules b oxygen gas c ions what helps water move across the membrane quicker? a aquaporin b photosynthesis c cytoplasm

Explanation:

1. Facilitated diffusion is a passive - transport process that does not require ATP as it moves substances down their concentration gradient with the help of protein channels.
2. Small non - polar molecules like oxygen gas can move easily across the membrane by simple diffusion without the need for facilitated diffusion. Polar molecules and ions generally require facilitated diffusion.
3. Aquaporins are channel proteins that help water move across the membrane more quickly. Photosynthesis is related to energy production in plants and the cytoplasm is the gel - like substance inside the cell, neither of which directly helps water move across the membrane faster.

Answer:

1. A. ATP
2. B. oxygen gas
3. A. aquaporin