Question

example of a protein pump; transport sodium ions out of the cell and potassium ions into the cell. glycolipids peripheral proteins sodium-potassium pumps glycoproteins

Explanation:

The problem is about the sodium - potassium pump, which is a concept in cell biology (a subfield of Biology). The sodium - potassium pump is a type of protein pump that transports sodium ions out of the cell and potassium ions into the cell, and this is a key topic in Biology, specifically in the study of cell physiology and membrane transport.

Answer:

The subfield is Biology (specifically related to cell biology and membrane transport mechanisms).