Lecture 7 (Ch 11) Flashcards
T/F: Bacteria chromosome organized into chromatin
F- eukaryotic
Chromatin state is important for gene expression– ___ is expressed and ___ isn’t
euchromatin vs. heterochromatin
Chromatin is ___
DNA + proein
Protein of chromatin control ___ and ___
structure and function
DNA compaction is achieved via 2 fold steps:
- 10 nm fiber
2. 30 nm fiber
Nucleosome = __ + __
Histone + DNA wrapped around it x2
10 nm fiber: Nucleosome has 8 subunits called ___; the individual name of them are ___
histones; H2A, H2B, H3, and H4 (x2)
10 nm fiber: in nucleosome, ___ and ___ form dimers; ___ and ___ form dimers
H2A + H2B
H3 + H4
10 nm fiber: nucleosome’s dimensions are:
11 nm diameter, 5.7 nm thickenss
10 nm fiber: has 3 parts. Which is conserved and which is variable?
nucleosome, core DNA, linker DNA;
former 2 conserved, latter 1 variable
10 nm fiber: core DNA has ___ bp
146
10 nm fiber: linker DNA has ___ bp
50-100 bp
T/F: H1 dimerizes with H2A
F. H1 not part of 10 nm fiber
30 nm fiber: 10 nm fiber coil into ___
solenoids
30 nm fiber: solenoids contain ___ per turn
6-8 nucleosome
30 nm fiber: H1 histone’s funciton is to ___
stabilize the solenoid for an additional level of condensation.
30 nm fiber: H1 histone is believed to wrap around ___
linker DNA
Metaphse Chromosome is additionally condensed via ___ that form ___ that form ___ that form ___
non-histone scaffolding proteins to form chromatin loops; they form rosettes that form bundles.
Max level of condensation is achieved in ___, achieved with the help of ___
mitotic chromosome;
condensin
DNA Replication: nucleosome ___ during passage of replication fork
diassemble transiently
DNA Replication: T/F: the daughter and the mother nucleosome will reassemble semiconservatively across daughter and mother strand
F. Histone dimers disassemble and reassemble at random
Histones: T/F they are considered small at 100 kbp
F. they are considered small, but at 11-14 kbp
Histones: are rich in ___ AA, which makes them ___.
lys; basic (:N)
Gene Expression: If promotor is at the core DNA, _____ conformation of transcription. If promotor is at the linker DNA, _____ conformation of transcription
closed; open
