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. This transport protein would best be described as __________.

Question

Quizplus · Accepted Answer

The transport protein is allowing the movement of both sodium and glucose across the plasma membrane, making it a symporter. A channel would allow only one type of ion or molecule to pass through, while a carrier protein would only move one type of molecule at a time. A pump requires energy to actively move substances against their concentration gradient, which is not happening in this case.

A Type of Transport Protein Found in the Plasma Membrane