Chromatín

Chromatin is the complex of DNA and proteins that forms chromosomes within the nucleus of eukaryotic cells. It serves to compactly pack DNA into a smaller volume to fit into the nucleus, to reinforce the DNA to allow mitosis and meiosis, and to serve as a mechanism to control gene expression and DNA replication. The primary proteins in chromatin are histones, which are responsible for the structural organization of the DNA. DNA wraps around histone proteins to form nucleosomes, which are the basic repeating units of chromatin. These nucleosomes are further coiled and folded to form more compact structures, ultimately leading to the formation of visible chromosomes during cell division. The precise arrangement and modification of chromatin play a crucial role in regulating gene activity, determining which genes are accessible for transcription and which remain silenced. This dynamic structure allows cells to manage their genetic material efficiently and respond to various cellular signals.