Video Transcript
When glucose is not being used, it
can be stored in the liver as an insoluble compound. What is the compound it gets stored
as?
You may recall that glucose is the
main reactant for cellular respiration, the chemical reaction which takes place in
every cell of the body to release energy. During intense exercise, our
muscles require lots of energy, so the rate of respiration is high. This means lots of glucose is being
consumed.
On the other hand, at rest, far
less energy is required. So the rate of respiration is
low. Therefore, very little glucose is
being consumed. During periods of low glucose
consumption, rather than the excess glucose remaining in the blood, where it can
damage the blood vessels, it is instead taken up by cells, primarily those of the
liver. In the liver cells, glucose is
converted into glycogen to be stored.
If we compare the structure of
glucose and glycogen, we can see that glycogen is just a long, branched polymer of
glucose molecules. Unlike glucose, glycogen is
insoluble. So it will not disturb the osmotic
balance of the liver cells, making it an ideal storage molecule.
We have therefore determined that
the compound glucose is stored as in the liver is glycogen.
