The integral proteins that carry out facilitated transport fall into which two functional classes?

1. The integral proteins involved in facilitated transport are collectively called transport proteins. 2. They function as either channels for the material or as carriers. 3. In both cases they are transmembrane proteins, spanning the whole bilayer. 4. Receptors, integrins and clathrin all exist in or at membranes, but none of them names this two-way split. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 5 "Structure and Function of Plasma Membranes", section 5.2 Passive Transport_