Question 23M.1A.SL.TZ2.4

The diagram shows protein channels involved in the passive movement of a substance into the cell across the cell membrane.

What describes this movement?

A.  Energy of ATP is used to transport substances into the cell.

B.  Substances can move from areas of low to areas of high concentration.

C.  The proteins ensure that movement of substances is only in one direction.

D.  Net movement occurs until the concentrations in and out of the cell are equal.