Understanding:
• Eukaryotic chromosomes are linear DNA molecules associated with histone proteins
The genetic material of eukaryotic cells consist of multiple linear molecules of DNA that are associated with histone proteins
- The packaging of DNA with histone proteins results in a greatly compacted structure, allowing for more efficient storage
Organisation of eukaryotic chromosomes can be summarised as follows:
- DNA is complexed with eight histone proteins (an octamer) to form a complex called a nucleosome
- Nucleosomes are linked by an additional histone protein (H1 histone) to form a string of chromatosomes
- These then coil to form a solenoid structure (~6 chromatosomes per turn) which is condensed to form a 30 nm fibre
- These fibres then form loops, which are compressed and folded around a protein scaffold to form chromatin
- Chromatin will then supercoil during cell division to form chromosomes that are visible (when stained) under microscope
Organisation of DNA in Eukaryotic Chromosomes
