Sollars - DNA Replication II (Eukaryotes)

Question 1

What can be said on the distribution of mitochondrial genomes?

Answer 1

2 - 10 copies
Cytoplasmic segregation
Heteroplasmy (uneven distribution)

Question 2

What pathology is common in mitochondrial DNA disease?

Answer 2

Liver pathology

Question 3

For MtDNA disease, what is the effect of Heteroplasmic vs Homoplasmic?

Answer 3

Heteroplasmic is rare, and strong (multisystem, death)

Homoplasmic is more common, and weaker (associated w/disease)

Question 4

Why would someone being treated for HIV-1 or Hepatitis B be affected by Mitochondrial DNA Depletion?

Answer 4

gamma-Pol resembles HIV polymerase (which we attack)

Question 5

What do MtDNA diseases in the exonuclease domain deal with?

Answer 5

Proofreading—fidelity

Question 6

What do MtDNA diseases in the polymerase domain deal with?

Answer 6

Efficiency

Question 7

What is the role of y-Pol (gamma)?

Answer 7

Replicates MtDNA

Question 8

What can occur when checks in the cell cycle to not properly occur to ensure fidelity of genome?

Answer 8

Cancer

Question 9

What is faster, prokaryotic or eukaryotic DNA replication?

Answer 9

Prokaryotic (50 bp/s vs 1000 bp/s)

Question 10

If you see a DNA Pol + Greek symbol, what are you dealing with?

What about a Roman numeral?

Answer 10

Eukaryote = Greek

Prokaryote = Roman

Question 11

What enzyme acts on the unrprotected end of linear chromosomes? What other problems can occur

Answer 11

Exonuclease

Chromosomal fusion events

Question 12

Cellular Senescence

Answer 12

Phenomenon which normal cells cease to divide, possibly triggered by gradual loss of telomere

Question 13

Cellular Crisis

Answer 13

When Cellular Senescence does not occur, and cells continue to divide–can lead to mutation events and cancer

Question 14

Telomerase

Answer 14

Enzyme to replicate end of chromosomes

Question 15

When will a cell enter Senescence?

Answer 15

When it reaches Telomere Associated Repeats (TAR)

Question 16

What is the mechanism for Telomere building?

Answer 16

After removal of original RNA primer, will have stretch of ssDNA

1. Telomerase contains RNA template matching telomeric repeat element
2. ssDNA above is extended farther
3. Primase synthesized RNA primer
4. 3’ ends of primer accepts DNA polymerase
5. RNA primer removed from 5’ end