The food which we eat provide us energy.Food is divided in many groups,but the food which give us energy after digestion,belong to three broad groups,namely, Carbohydrate ,Protein and fat.Sugar belong to carbohydrates called Saccharides .Sugar is mono ,sucrose is di and starch,cellulose and glycogen are all poly saccharides.We eat mainly poly saccharides ,unless we eat too much sugar.
Saccharides start breaking in mouth and ultimately reaches small intestine.Here sugar is absorbed and sent first to Liver.The liver has certain properties.It can reassemble saccharides into polysaccharide called Glycogen,which is storage form of glucose.When blood sugar goes down liver make certain hormones and make glucose from glycogen and send it back to blood circulation.
So from liver glucose goes into general circulation so that cells can utilise it for energy or storage.It is stored mainly in Heart muscles,skeletal muscles and adipose or fat cells.
Here comes the role of pancreas.The presence of sugar in blood is sensed by pancreas which produces a hormone,Insulin.But the problem here is two fold,(1)insulin by itself can not enter cell,so it need some help to enter the cell,so it attaches itself to insulin receptors which are situated on the surface of cell,which take insulin inside the cell. (2)Glucose by itself also can not enter the cell,so it needs a transporter to carry it inside the cell.
Now inside the intestinal cells are glucose transporters,called GLUT4 ,these have to be sent to the cell membrane to bring glucose inside the cell.when insulin gets inside a cell it initiate a complex process which ultimately move glucose transporters to the cell membrane and glucose comes inside the cell,where it can be utilised to get energy.
TO. BE CONTINUED.... .........