A transporter that carries two different ions in opposite directions is called what?

1. A uniporter carries one specific ion or molecule. 2. A symporter carries two different ions or molecules, both in the same direction. 3. An antiporter carries two different ions or molecules, but in different directions. 4. Aquaporins are water channels and are not one of the three transporter types. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 5 "Structure and Function of Plasma Membranes", section 5.3 Active Transport_