1. Moves molecules from high to low concentration II. Moves molecules with the concentration gradient
10. 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
applies ONLY to facilitated diffusion and NOT diffusion?

A)V and VI
B)IV and Vl
C)II and IV
D)III and IV