BCHM 4360 - Exam 1: Chapter 4
Terms in this set (169)
Humans 46 chromosomes
Kingfisher 132 chromosomes
Dogs 78 chromosomes
Fission Yeast 6 chromosomes
IHF Bacterial protein that binds DNA and bends it
DNA plus proteins in bacteria
Nucleoid Compacted bacterial chromosome
Proteins bend the DNA which causes supercoiling
Four Core Histones H2A, H2B, H3, and H4
Tetramer H3 and H4 form a(n)
Heterodimers H2A and H2B form
N-terminal tail All core histones have a(n)
Sharp bends Usually at pyrimidine-purine sequences: TA or CG
Minor groove Needs to be narrow during bending, more favorable in AT rich
regions
First level of DNA packaging
Arises from nucleosome
10 nm fiber
association with DNA Beads on a
string appearance
10 nm is folded further into
30 nm fiber
Regular arrangement that brings nucleosomes together
Linker histone that helps in the formation of the 30 nm fiber
H1
Binds to linker DNA that connects successive
nucleosomes, facilitating the compaction of the
chromatin
Stains lightly
Less
Euchromatin
compact/condens
, ed Genes are
actively transcribed
Stains darkly
Heterochromatin More compact/condensed
Less transcription, prevents transcription, silences genes
H2A and H2B Have a C-terminal tail that can be modified
H3 and H4 Can be modified at their cores
quitination This can occur on H2A and H2B but not on H3 and H4
H2A No methylation
Histone acetyltransferases Add acetyl groups to lysine side chains
(HATs)
Histone deacetylases (HDACs) Remove acetyl groups from lysine side chains
Histone methyltransferases Add methyl groups to lysine and arginine side chains
(HMTs)
Histone demethylases Remove methyl groups from lysine and arginine side chains
Terms in this set (169)
Humans 46 chromosomes
Kingfisher 132 chromosomes
Dogs 78 chromosomes
Fission Yeast 6 chromosomes
IHF Bacterial protein that binds DNA and bends it
DNA plus proteins in bacteria
Nucleoid Compacted bacterial chromosome
Proteins bend the DNA which causes supercoiling
Four Core Histones H2A, H2B, H3, and H4
Tetramer H3 and H4 form a(n)
Heterodimers H2A and H2B form
N-terminal tail All core histones have a(n)
Sharp bends Usually at pyrimidine-purine sequences: TA or CG
Minor groove Needs to be narrow during bending, more favorable in AT rich
regions
First level of DNA packaging
Arises from nucleosome
10 nm fiber
association with DNA Beads on a
string appearance
10 nm is folded further into
30 nm fiber
Regular arrangement that brings nucleosomes together
Linker histone that helps in the formation of the 30 nm fiber
H1
Binds to linker DNA that connects successive
nucleosomes, facilitating the compaction of the
chromatin
Stains lightly
Less
Euchromatin
compact/condens
, ed Genes are
actively transcribed
Stains darkly
Heterochromatin More compact/condensed
Less transcription, prevents transcription, silences genes
H2A and H2B Have a C-terminal tail that can be modified
H3 and H4 Can be modified at their cores
quitination This can occur on H2A and H2B but not on H3 and H4
H2A No methylation
Histone acetyltransferases Add acetyl groups to lysine side chains
(HATs)
Histone deacetylases (HDACs) Remove acetyl groups from lysine side chains
Histone methyltransferases Add methyl groups to lysine and arginine side chains
(HMTs)
Histone demethylases Remove methyl groups from lysine and arginine side chains
