【单选题】Which of the following statements about membrane transporters is wrong?
A.
Membrane proteins that act by increasing the rate of solute movement across membranes are called transporters or carriers.
B.
Transporters are of two general types. Passive transporters simply facilitate movement down a concentration gradient, increasing the transport rate. This process is called passive transport or facilitated diffusion.
C.
Active transporters (sometimes called pumps) can move substrates across a membrane against a concentration gradient or an electrical potential, a process called passive transport.
D.
Primary active transporters use energy provided directly by a chemical reaction; secondary active transporters couple uphill transport of one substrate with downhill transport of another.