Question

Glucose enters erythrocytes via a GLUT-1 uniporter. As the levels of glucose in the bloodstream decrease between meals, what happens to the glucose in the cells? A. Glucose leaves the cell through the GLUT-1 uniporter, traveling down the new concentration gradient. B. Glucose remains in the cell because uniporters can only transport in one direction. C. Glucose remains in the cell because the GLUT-1 uniporters are gated and the gates close at low glucose concentrations. D. Glucose remains in the cell because it has been phosphorylated and no longer has affinity forthe GLUT-1 uniporter.

Answer 1

Answer:

A. Glucose leaves the cell through the GLUT-1 uniporter, traveling down the new concentration gradient.  

Explanation:

The Glucose transporter 1 (GLUT1) protein is a critical uniporter transporter that facilitates the movement of glucose molecules across the plasma membrane. The expression of GLUT1 is increased when glucose concentration is reduced and, inversely, GLUT1 expression is reduced when glucose levels are increased. The erythrocytes are cells that continuously require the supply of glucose from the blood plasma, this mechanism involves the function of GLUT1 that permits the energy-free passage of glucose by diffusion.