chromatin

Introduction

In eukaryotes nuclear chromosomes are packaged by proteins (especially histones) into chromatin to fit the chromsomes into the nucleus. Histones package the chromsomes into nucleosomes which may be furthe organized into solenoids. The structure of chromatin varies through the cell cycle, & is responsible for the compaction of DNA into the classic four-arm structure during mitosis & meiosis. Prokaryotes do not form chromatin, because the cells lack proteins required & the circular configuration of the molecule prevents this.

More general terms

• macromolecular complex

More specific terms

• euchromatin
• heterochromatin
• sex chromatin