Question

i. moves molecules from high to low concentration
ii. moves molecules with the concentration gradient
iii. does not require energy
iv. requires the use of a membrane protein
v. used to move small and/or nonpolar molecules
vi. used to move large and/or polar molecules
cell membranes are selectively permeable, regulating which substances can pass through, as well as how much of each substance can enter or exit at a given time. in cells, some molecules can move down their concentration gradients by crossing the phospholipid portion of the membrane directly, while others must pass through membrane proteins. which of these statements does not apply to facilitated diffusion?
a ii
b iv
c v
d vi

Explanation:

Facilitated diffusion is passive (no energy, III), moves down the concentration gradient (I, II), uses membrane proteins (IV), and transports large/polar molecules (VI). Small/nonpolar molecules use simple diffusion (V does not apply).

Answer:

C. V