Chromatin

"In this animation we'll see the way our DNA is tightly packed up to fit into the nucleus of every cell. The process starts with assembly of a nucleosome, which is formed when eight separate histone protein subunits attach to the DNA molecule. The combined tight loop of DNA and protein is the nucleosome. Six nucleosomes are coiled together and these then stack on top of each other. The end result is a fiber of packed nucleosomes known as chromatin."

Essential Cell Biology, Second Edition
by Alberts, Bray, Hopkin, Johnson, Lewis, Raff, Roberts, Walter
copyright 2004 by Garland Science Publishing

Category:

Science & Technology

Tags:

• DNA
• deoxyribonucleic
• acid
• nucleus
• organelle
• nucleosome
• core
• particle
• linker
• histone
• protein
• chromatin
• chromosome
• cell
• biology
• biochemistry
• science

[newkel90]

are u sure that nucleosomes are arranged in such a symmetrical stack? shouldnt it be an irregular, fluctuating, 3-dimensional zigzag structure instead?

[leaffan27]

Nucleosome and basic chromatin structure is well known.....however, levels of folding beyond that are currently only hypothetical.

Furthermore, there will be transcriptionally-active areas of the genome which are more accessible, as well as down-regulated areas. Functional groups such as CH4 can be present as well. In fact, there are lots of DNA modifications that are beyond the scope of this video.

[rom1bis]

Do you think histones are attached, fixed to a defined peace of DNA? or can they move, slide along DNA like beads on a string?...

[zakmatew]

@leaffan27 Did you mean CH3?

[Lakia08]

this is oddly gross...but very helpful. thank you

[theIlluminous1]

why

does it seem so sexual?

[fulanaarvore]

@leaffan27 thanks for both the video and the explanation!

[IHaveWings90]

Thank you so much!

[Pimpmastahanhduece]

i bet they slide, it just seem to displace the bonding angle of the phosphate links, im pretty sure when copying code to rna they move out of the way for the scanning/copying mechanism.

[Ov3ract1ve]

thx for the vid!