Chapter 5, Problem 3CHI

Summary Introduction

The nucleus is one of the largest organelles in the cell and that contains chromosomes. Eukaryotic chromosomes are composed of a complex of DNA and protein structure is known as chromatin. The chromatin structure serves for the packing and condensation of DNA molecules, thereby; the large size of DNA molecules can be inserted into the cell. There are five histone proteins are found in eukaryotes such as H1, H2A, H2B, H3, and H4. Eight molecules of histones create a structure called an ellipsoid containing 11 nm in long and 6.5-7 nm in diameter. The DNA wraps around the ellipsoid and produces a “beads on a string” formation. Each bead is known as a nucleosome. The highly compacted structure of the chromosome is found during cell division. Histones proteins and other molecules, mainly contribute to the compact structure of chromosomes.