What is Chromatin:
Chromatin is a substance in eukaryotic cells made up of a combination of proteins called “histones”, with DNA and RNA, whose function is to shape the chromosome so that it is integrated into the nucleus of the cell.
Chromatin is modified throughout the stages of the cell cycle, generating various levels of compaction.
Histones are basic proteins made of arginine and lysine. Their function is to make it easier for the DNA to compact to integrate into the cell nucleus. This, in turn, is responsible for providing genetic information to the cell.
Thus, the first thing chromatin does is facilitate the union of DNA with a nucleic aggregate that produces the so-called nucleosomes.
In turn, the numerous nucleosomes generate a structure known as a "pearl necklace", due to the shape that results.
At the next level of compaction, the structure transforms into a solenoid. From there follow the transformation stages until reaching the shape of the chromosome as we know it.
Chromatin compaction levels.
There are at least two types of chromatin. Namely: heterochromatin and euchromatin.
In heterochromatin, the filaments condense and wind together to form a kind of bulge. DNA remains inactive, as this condensation process does not allow it to encode genetic material.
Euchromatin, for its part, refers to the type of chromatin where condensation is less, which allows the active presence of DNA, capable of reading genetic codes under these conditions.
- Cell parts