Question

Click Next until you get to the Facilitated Diffusion model. Then fill in the blank using all lower case letters, and watch your spelling!

Facilitated diffusion

require ATP, and requires
channel
. These are also called

, which bring molecules across the cell membrane from areas of
concentration to areas of
concentration

(
the concentration gradient).

Answer 1

Facilitated diffusion

does not require ATP, and requires
channel
proteins. These are also called
transport proteins, which bring molecules across the cell membrane from areas of
high concentration to areas of
low concentration

(against the concentration gradient).