Amylopectin
Amylopectin
Amylopectin is an organic molecule and represents the insoluble fraction of starch (about 80%), which constitutes the external part of the granule.
It is a molecule very present in the plant world.
The amylopectin content of starch varies from one species to another.
It ranges from 78% in the potato, banana and seeds of some cereals (such as wheat, rice and corn), up to 99% of other cereals.
This molecule, made up of numerous chains, branched and linked together, of glucose molecules, has a brute or molecular formula: (C6H12O6) n.
In amylopectin the monosaccharide components (glucosides) are linearly linked together by means of α-type bonds (1 → 4); the ramifications occur with bonds of type α (1 → 6), every 24-30 units of glucose.
The structure of amylopectin is such that the number of glucose molecules present can vary from 2,000 to 200,000.
During the hydrolysis of amylopectin which occurs, inter alia, in the seed germination process, the α (1 → 4) bonds are dissolved by the α- and β-amylase enzymes and the consequent production of dextrins (smaller segments containing bonds of type (1 → 6)) which will subsequently be attacked by other enzymes called dextrinases.
This process which is accompanied by the degradation of amylose, causes the demolition of the starch in units such as maltose and glucose.
A similar molecule of amylopectin is glycogen, present in animals, and with the same composition and structure, but with a higher degree of branching (every 8-12 units of glucose).
In plant species, starch accumulates within some organelles that take the name of amyloplasts.
The function of the starch, inside the plants, is energetic as it is a reserve that is necessary for cellular work; when energy processes are needed, plants hydrolyze the starch by releasing the glucose units.
At the animal level, as in humans, there are particular enzymes that hydrolyze starch for energy needs.
In the human species, amylopectin represents the most digestible and assimilable fraction of starch, while amylose tends to behave like a non-assimilable fiber.
Warning: The information shown is not medical advice and may not be accurate. The contents are for illustrative purposes only and do not replace medical advice.