Question

How does a liver cell store excess glucose without becoming hypertonic (think about osmotic pressure!)?

Group of answer choices

It assembles glucose into one large solute, glycogen

It stores it in an impermeable organelle

It rapidly and completely catabolizes glucose to ATP

It has special water pumping membrane proteins

Answer 1

Glucose is very soluble, so it can change the osmotic presseure of the cell by making it hypertonic in nature. So, if an excess amount of glucose is stored in the liver cell, it will become hypertonic, that would elicit the water molecule to enter into the cell by osmosis and then the liver cell will burst.

So, the excess amount of glucose is stored in the liver cell as glycogen (Glycogen is biopolymer consisting of linear chains of glucose residues with an average chain length of approximately 8–12 glucose units which are linked together linearly by α(1→4) glycosidic bonds from one glucose to the next and are linked to the chains from which they are branching off by α(1→6) glycosidic bonds between the first glucose of the new branch and a glucose on the stem chain.) Because glycogen is insoluble, so it will not alter the osmotic condition of the liver cell. In liver cell, at first glucose is converted to gucose-6-phosphate, Glucose 6-phosphate is isomerized into glucose 1-phosphate and then converted into UDP–glucose by UGP. UDP–glucose is the immediate glucose donor for glycogen synthesis.