Flashcards
Th2L02 DNA repair mechanisms
Cards in this deck (24)
- 1What is the role nucleaseRemoves the wrong nucleotide added by polymerase
- 2Which direction does (exo)nuclease work3-5'
- 3What enzyme adds the correct nucleotides back to the DNADNA polymerase with ATP
- 4What does exonuclease preventthe accumulation of mutations
- 5What is the overall, final error rate of eukaryotic DNA after exonuclease activity1 in 10^10 or 1 in every 100 billion bases
- 6Mutated genes result in whatabnormal proteins
- 7What are two pathogenic things than can happen as a result of abnormal proteinsimportant loss of function OR gain in toxic function
- 8What are most cancer cells in mammals caused bypoint mutations in proteins that control cell growth
- 9What is the end replication paradoxThe ends of linear chromosomes are lost after each round of replication, and once the RNA primers have been removed, the lagging strand is shorter than the leading strand at the 5' end
- 10What are teleomeresA long region of repetitive nucleotide sequences at each end of a chromatid, which protects the end of the chromosome from deterioration or from fusion with neighbouring chromosomes
- 11What addresses the end replication paradoxteleomeres
- 12What is teleomerasean enzyme that catalyses the lengthening of telomeres
- 13What is teleomerase accompanied bya short-strand of RNA that serves as a template for new telomere segments (as opposed to using a chromosomal template)
- 14What is the relationship b/w somatic cells and telomereaseTelomerase is turned off so with every division the telomeres get shorter
- 15What is the Telomerase catalytic protein component (2)Activates telomerase activity
Extends the length of telomerase and extends the lifespan by more than 5 times - 16What does the telomerase catalytic protein component suggestthat your lifespan is limited by telomere length rather than vice versa
- 17What is SenescenceThe natural physical decline brought about by aging
- 18What cells human maintain telomerase activity into adulthood, necessary for carrying complete genes on to our progenyGametes
- 19What is the Hayflick limit• The number of times a human cell is capable of dividing into two new cells
• The limit for most human cells is approximately 50 divisions, an indication that the life span is limited by our genetic programme - 20What is the role of the RNA templateIt combines with DNA overhang, serving as an anchor site for to telomerase interacts with DNA
It directs sequential nucleotide addition, extending the 3' end of the chromosomal DNA - 21What is the RNA templateA template, short than a telomere but with a shift than allows for the RNA template to shift forwards and begin copying the template again
- 22What is direct repairDNA repair in which modified bases are changed back into their original structure via removal of damaged region followed by re-synthesis
- 23What are the forms of direct DNA repairR
- 24What is nucleotide excision repair (NER)Distorted helix results in region around damage removed by nuclease and helicase action > re-synthesis
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- User has deleted their subject information Flashcards on Th2L02 DNA repair mechanisms, created by Deleted user on 26/08/2016.
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- Deleted user · Aug 2016
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- Aug 27, 2016
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- Created by Emma Allde · Aug 21, 2016
- Copied by Emma Allde · Aug 26, 2016
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