# Carrier Proteins --- **Carrier proteins** are a type of [[membrane transport protein]] that that allow the transport of large or polar molecules that would otherwise not make it though the membrane. First the solute binds to the protein, the protein then undergoes a conformational change (which brings the solute to it's desired destination), then the solute releases from the carrier proteins, which changes back to it's original shape. ![[carrier protein.png]] Carrier proteins can either be *uniporters* or *cotransporters*. - **Uniporters** transport only one substance. - **Cotransporters** transport more than one. Cotransporters can further be classified as *symporters* and *antiporters*. - **Symporters** transport their molecules both in the same direction - **Antiporters** transport them in opposite directions. ___