Cell Nucleus

cell cycle

lasts about 12-18 hours, with mitosis only aking about 20 minutes

heterochromatin

appears dark on a micrograph

euchromatin

appears light on a micrograph

what is the state of chromatin in the nucleus

exist as a biomolecular condensate

how many nucleotides are wrapped arond each hsitone

146

Disproved heirarchy of chromatin

• Dna double helix

• beads on a string

• 30 nm fiber

• 300 nm fiber

• condensed chromatin

• chromosome

what drives heterochromatin domain formation

phase separation

bacterial transcription regulation

activator binds to promoter/operator region

eukaryotic transcriptional regulation

requires several transcription factors and foldng of enhancer

nuclear pores

• are always the same

• small things can passively move thru

• larger things are transported in by specific factors

hutchinson gilford progeria syndrome

• premature aging

• nuclear lamin is not assembled properly so the nucleus is left unsupported

• falls apart

wash

interacts with lamin and affects global nuclear orgaization