structure of the prokaryotic genome Flashcards
1
Q
what does the prokaryotic genome consist of?
A
- a single circular double-stranded DNA &/or
- extrachromosomal plasmids
2
Q
where is the prokaryotic genome found in?
A
- in the nucleoid region in the cytosol,
- & it is not enclosed by a nuclear membrane
3
Q
what does the prokaryotic chromosome consist of?
A
- it consists of 1 circular double-stranded DNA molecule,
- with only 1 origin of replication
4
Q
what are the characteristics of the DNA molecule?
A
- it is highly condensed, with numerous nucleoid-associated proteins bound to the DNA,
- with each domain being negatively supercoiled
5
Q
what do the nucleoid-associated proteins that bind to the DNA do?
A
- they compact & fold the chromosomal DNA into domains
6
Q
what is the enzyme that catalyse the negative supercoiling of DNA?
A
- DNA gyrase
7
Q
what is the function of DNA gyrase?
A
- it allows for further compaction of the prokaryotic chromosome
8
Q
what is negative supercoiling?
A
- negatively supercoiled DNA is when the double helix is twisted against the helical conformation (left-handed twist)
9
Q
are nucleoid-associated proteins histone?
A
- NO THEY ARE NOT HISTONES
- PROKARYOTES DO NOT NEED HISTONES
10
Q
what is the highly condensed chromosome called?
A
- it is called a folded genome
