What is the main function of GLUT 2?

The main function of GLUT 2 is related to glucose transport. GLUT 2 is a glucose transporter that primarily facilitates the transport of glucose across cell membranes, particularly in the liver, pancreatic beta cells, and the kidneys. This transporter operates in a bidirectional manner, allowing glucose to enter or exit cells depending on the concentration gradient.

In the context of the liver, GLUT 2 plays a crucial role in regulating blood glucose levels. When blood glucose levels are high, GLUT 2 promotes the uptake of glucose into liver cells, where it can be stored as glycogen or converted into fatty acids through lipogenesis. Conversely, when blood glucose levels drop, GLUT 2 allows glucose to be released back into the bloodstream to maintain homeostasis.

While glucose storage is a consequence of GLUT 2’s function in the liver, it is not the sole function of this transporter; rather, it also facilitates glucose uptake and release in response to blood glucose concentrations. This dual role highlights GLUT 2's importance in maintaining energy balance in the body.

In contrast, options related to the transport of fatty acids, protein synthesis, and uptake of amino acids do not accurately describe the function of GLUT 2, which is specifically focused on glucose transport and regulation within the body.