Phosphorylation at the beginning of glycolysis

Question

What are the main purposes of glucose being phosphorylated once it enters the cell through glucose transporters? What would happen if glucose is not phosphorylated once it enters the cell?

Answer 1

The purpose of phosphorylation is to "trap" the glucose within the cell. This is important because glucose likes to travel through our blood and when it reaches the tissues where it is needed, it is able to diffuse into cells via GLUT transporters but without the phosphorylation, the glucose could just leave the cell. Phosphorylation also allows for glucose to be used via multiple pathways for multiple reasons like being converted into glycogen, being broken down into pyruvate, entering the pentose phosphate pathway, etc. If glucose was not phosphorylated upon entering the cell, it would be unable to be used for these pathways and it would just return back to the blood and our cells our be starved of energy from it.