Mitochondrial DNA Flashcards Preview

Genetics of cell growth and division > Mitochondrial DNA > Flashcards

Flashcards in Mitochondrial DNA Deck (14)
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1
Q

what are the main elements of the mt genome?

A

non-coding D loop, HSP, LSP, OH, OL

2
Q

why do mt genomes vary in size between species?

A

number of introns and genes encoded

3
Q

copy number in somatic and copy number in oocytes

A

20-200 and 200,000

4
Q

what is different in bacterial mt genomes?

A

has variation in triplet code

5
Q

what ETC complex is just encoded by nuclear DNA?

A

complex 2

6
Q

what needs to be transcribed for transcription to occur?

A

section of LSP

7
Q

nuclear encoded things required for replication

A

transcription factors, co factors and polymerases

8
Q

how does TFAM work?

A

binds LSP and transcribes entire light strand and generates RNA primer for replication. RNA/DNA transition, then replication of OH from HSP and replication of light strand once OL exposed

9
Q

the only mt polymerase

A

PolG

10
Q

what happens when TFAM knocked out?

A

homozygous= severe mtDNA depletion, abolished OXPHOS, enlarged mt, growth retardation, lethal at E10.5
in heterozygotes= reduced mtDNA copy number, transcription and get respiratory chain dysfunction

11
Q

overall what is the role of TFAM?

A

maintain mtDNA copy number and respiratory chain function. Also essential for replication of mtDNA. Also may have packaging role in nucleoids

12
Q

why are nucleoids important?

A

they regulate stability, replication, transcription and segregation of mtDNA

13
Q

what does TFAM binding do to DNA?

A

binds LSP and HSP and bends it into a U shape

14
Q

how many nuclear encoded products are essential for mt function?

A

over 1000