DNA Replication II Flashcards
How are mitochondria distributed during cell division?
It is random, there is no strict process to segregation
What is heteroplasmy?
Mt Genomes in individual cells are different
What is characteristic of strong effect mitochondrial depletion syndrome mutations?
They are rare and heteroplasmic
What is Mitochondrial DNA depletion syndrome?
Metabolic defects in replication of mitochondrial DNA result in deletion of this DNA and pathology is characterized by multi-organ disturbance
Who do mtDNA depletion syndromes affect?
Children
Those treated for HIV1 and Hep B virus
Young adults
Describe the origins of replication in eukaryotes.
Multiple origins
AT rich but not really specific
What is the function of DNA pol alpha?
Contains primase and initiates DNA synthesis
What is the function of DNA pol beta?
Repair
What is the function of DNA pol gamma?
Replicates mitochondrial DNA and proofreading
What is the function of DNA pol delta?
Elongates okazaki fragments of the lagging strand and proofreading
What is the function of DNA pol epsilon?
Elongates the leading strand and proofreads
What phase of the cell cycle does DNA synthesis occur?
The S phase
How is eukaryotic replication different from prokaryotes?
More complex
Much slower
Origins aren’t specific and AT rich
Telomere replication
Nomenclature follows greek symbols
What are the problems with linear chromosomes?
Need to protect ends from degredation
Preventing chromosomal fusion
Full replication of the cell ends
What is the general structure of a telomere?
Buffer region of 100-300kb telomere associated repeats
3-20kb region of tandem TTAGGG repeats
Single stranded region folded upon itself and bound by proteins
