Sodium concentrations are higher outside and glucose concentrations are higher inside the cell.Using the same membrane protein for Na⁺ and glucose transport,what is it called when a Na⁺ electrochemical gradient is used to drive glucose transport into the cell against its concentration gradient? A)Primary active transport B)Secondary active transport C)Primary facilitated diffusion D)Secondary facilitated diffusion E)Passive diffusion

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Quizplus · Accepted Answer

This is an example of secondary active transport, where the electrochemical gradient of one molecule (sodium) is used to drive the transport of another molecule (glucose) against its concentration gradient. In this case, the membrane protein is acting as a symporter, simultaneously transporting the two molecules in the same direction. Primary active transport would require the direct use of ATP to drive the transport, while facilitated diffusion (whether primary or secondary) does not involve the use of energy to move molecules against their concentration gradient. Passive diffusion refers to the movement of molecules down their concentration gradient without the use of a membrane protein.

Sodium Concentrations Are Higher Outside and Glucose Concentrations Are Higher