DNA Packaging in Cells

Overview

• DNA, measuring six feet in length, fits into the microscopic nucleus of every cell through a remarkable packaging process.

Packaging Process

1. DNA Wrapping Around Histones

   • DNA wraps around protein molecules known as histones.
   • This combination forms a structure called a nucleosome.

2. Formation of Chromatin

   • Nucleosomes are structured into a thread known as chromatin.
   • Chromatin is further looped and packaged, though the additional proteins involved are not detailed here.

3. Formation of Chromosomes

   • DNA is tightly packed into chromosomes, visible under a microscope.
   • Chromosomes form during cell division when the DNA's two copies need to be separated.

4. DNA Organization Post-Division

   • After cell division, DNA remains less organized, not coiled into chromosomes.
   • It stays wrapped around histones but is not as tightly packed as during chromosome formation.