Question

In the lumen of your small intestine, the Na+/glucose symport moves sodium and glucose in the same direction working together with the Na+/K+ active pump. What specific method of transport is used?

Answer 1

The Na+/glucose symporter in the small intestine uses secondary active transport to move glucose into the cell against its concentration gradient, utilizing the energy from the sodium gradient maintained by the Na+/K+ ATPase pump.

Step-by-step explanation:

The specific method of transport used by the Na+/glucose symporter in the small intestine is known as secondary active transport. This process involves the active transport of sodium ions out of the cell via a Na+/K+ ATPase pump, creating a concentration gradient. Glucose then enters the cell against its own concentration gradient through a symport mechanism with sodium ions. The energy from the sodium ion gradient, which is maintained by the ATPase pump, is used to 'pull' glucose into the cell via the symporter.

Thus, glucose and sodium are transported into the cell in the same direction through the Na+/glucose symporter. Sodium ions are then pumped out of the cell against their concentration gradient by the Na+/K+ ATPase pump, and glucose diffuses into the blood. This is essential to maintain a low sodium concentration in the cell, which is necessary for the continuation of glucose absorption through active transport.