A type of transport protein found in the plasma membrane of cells lining the inside of the intestine allows sodium ions to diffuse down their concentration gradient. The ions move through the transport protein, and into the cell. These transport proteins will use the kinetic energy of the diffusing sodium ions to bring glucose into the cells as well. Which of the following would stop transport of glucose through this transport protein?

Question

Quizplus · Accepted Answer

The transport protein relies on the movement of sodium ions down their concentration gradient to bring glucose into the cell. This movement of sodium ions is maintained by the sodium potassium pump, which actively transports sodium ions out of the cell to maintain a low concentration of sodium inside the cell. If the activity of the sodium potassium pump is stopped, the concentration gradient for sodium ions will eventually equalize, and there will be no gradient to drive the movement of glucose into the cell. Therefore, stopping the activity of the sodium potassium pump would stop transport of glucose through this transport protein.

A Type of Transport Protein Found in the Plasma Membrane