Genomic Structure and Organization Flashcards
1
Q
packaging of DNA in the nucleus in bacteria
A
- negative supercoiling
- compact structure is called nucleoid
- nucleoid exists in the cytosol with a few attachments to the membrane
2
Q
packaging of eukaryotic DNA in the nucleus
A
Dna is confined to the nucleus and wrapped around histones
3
Q
nucleosome
A
- DNA wrapped around histones
- portion of DNA that can’t be digested
4
Q
SINES
A
short interspersed elements
5
Q
LINES
A
long interspersed elements
6
Q
Alu sequences
A
-named bc Alu1 restriction site found in sequences
7
Q
intron sequences
A
- increases the size of the eukaryotic genome
- some eukaryotic genes (like histones) don’t have introns
8
Q
gene variants
A
- may be expressed in different tissues or at different stages of development
- some produced via alternate splicing, but many have a completely separate gene
9
Q
pseudogenes
A
- role is not understood
- not true gene!
10
Q
nuclear envelope
A
- contains pores to allow free diffusion of small molecules bw nucleus and cytoplasm
- exportins and importins assist with selective transport of RNA and protein
- since protein synthesis occurs in cytoplasm and mRNA synthesis occurs in nucleus, transcription and translation cant be directly coupled
11
Q
H1
A
- associated with linker DNA
- helps form higher order structure
- only histone not inside of histone core
12
Q
H2A and H2B
A
two of each form histone
13
Q
H3
A
octamer core of nucleosome
14
Q
euchromatin
A
chromatin during interphase that is active
15
Q
heterochromatin
A
chromatin during interphase that is transcriptionally inactive
