The document discusses P-type pumps, also known as SERCA pumps, which are membrane proteins that use ATP to transport ions across membranes. P-type pumps get their name because they use a phosphorylated protein intermediate in their reaction mechanism. Key facts are that they commonly transport calcium, sodium, and potassium ions, use a significant amount of the body's energy, can transport ions in both directions, help maintain osmotic potential and membrane resting potential, and regulate functions by establishing electrochemical gradients, such as the calcium pump in muscle cells.