We have the ptype Atpas that we're going to focus on in this lecture and we also have the ABC transporters. Now, what exactly is a ptype Atpas? Well, the P basically stands for phosphoryl. And in a ptype Atpas, they basically use ATP molecules, they hydrolyze NATP molecules, they use that phosphoryl group to attach it onto that membrane protein, that pump. And then that creates a conformational change in the pump that allows the pump to actually move the molecule against the electrochemical grading as we'll see in just a moment. And one well studied pump that we're going to focus on, one well studied ptype Atpas will be the calcium Atpas that we're going to focus on in this lecture.