Final answer:
Classes of membrane transport proteins include ATP-powered pumps, ion channels, and different types of transporters involved in selective ion and molecule movement. However, protein translocons are not involved in direct ion or molecule transport and do not fit into this categorization. The correct option is 1) ATP-powered pumps.
Step-by-step explanation:
The classes of membrane transport proteins include ATP-powered pumps, ion channels, and various types of transporters. ATP-powered pumps, like Na+-K+ ATPase and Ca2+ ATPase, use energy from ATP to move substances across the membrane against their concentration gradients. Ion channels serve as passages for ions to move down their concentration gradients, requiring no energy input. Transporters, which include uniporters, symporters, and antiporters, can operate in both active transport, requiring ATP, and facilitated diffusion, which does not require ATP. These transporters are involved in the selective movement of ions and molecules across the cell membrane.
However, protein translocons are not typically categorized as membrane transport proteins involved in the direct transport of ions or molecules across a cell membrane. Instead, they are involved in the translocation of polypeptide chains into or across membranes during protein synthesis.