Methods | Statistics | Clinical | Educational | Industrial |
Professional items | World psychology | Chromatin is the complex
of DNA and protein that makes up chromosomes. In eukaryotes
chromatin is found inside the nuclei of eukaryotic cells, while
in prokaryotes, the chromatin is held within the nucleoid. The
nucleic acids are in the form of double-stranded DNA (a double
helix). The major proteins involved in chromatin are histone
proteins, although many other chromosomal proteins have
prominent roles too. The functions of chromatin are to package
DNA into a smaller volume to fit in the cell, to strengthen the
DNA to allow mitosis and meiosis, and to serve as a mechanism to
control expression. Changes in chromatin structure are affected
mainly by methylation (DNA and proteins) and acetylation
(proteins). Chromatin structure is also relevant to DNA
replication and DNA repair. Chromatin is easily visualised by
staining, hence its name, which literally means coloured
material. Simplistically, there are three l