Science Word Wednesday: Nucleosome

Jan 13, 2021
By Riya Gohil

Nucleosome 

(Noun. /NEW-klee-uh-sohm/) 

What does it mean? 

A nucleosome is a unit of eight proteins (called histones) that DNA wraps around, like how thread wraps around a spool. If you stretch out the DNA inside a single human cell, DNA would be about 6 feet long! That’s a lot of DNA that needs to fit inside a nucleus of a cell, which is only about 100 micrometers wide on average. In order to package or condense DNA in an organized way to allow for it to fit into such a small space, DNA is wrapped around nucleosomes. 

 Diagram of a nucleosome highlighting the eight histones (blue) that make up the nucleosome unit, and DNA (red) wrapping around the histones. Linker DNA (purple) is the DNA between two nucleosomes. Source 

How do I use it in a sentence?

Whether a gene is transcribed depends on how tightly or loosely DNA is wrapped around nucleosomes

Fields of study in which this word is commonly used 

Genetics 

Related terms

Histones

DNA

Chromatin 

Heterochromatin 

Euchromatin 

Edited by Emma Goldberg and Anna Wheless