Question

1. how molecules move

diffusion: high → low, no energy.
facilitated diffusion: helper protein, no energy.
active transport: low → high, requires energy.
review questions:
which transport requires energy?
how is facilitated diffusion different from simple diffusion?

Explanation:

Diffusion is the movement of molecules from high - concentration to low - concentration areas without energy input. Facilitated diffusion also moves from high to low but uses helper proteins and no energy. Active transport moves molecules from low to high concentration and requires energy. For the first question, active transport requires energy as stated. For the second, facilitated diffusion uses helper proteins while simple diffusion does not.

Answer:

• Which transport requires energy? Active Transport
• How is facilitated diffusion different from simple diffusion? Facilitated diffusion uses helper proteins while simple diffusion does not.