Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chromosomes Exam 2 > 10/17 - DNA repair defects > Flashcards

10/17 - DNA repair defects Flashcards

1
Q

Chromosomal instability at molecular level: GENOME NUMBER

A

Effect: POLYPLOIDY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Chromosomal instability at molecular level: GENOME STRUCTURE

A

Effect: LOSS OF HETEROZYGOSITY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Chromosomal instability at molecular level: CHROMOSOME NUMBER

A

Effect: ANEUPLOIDY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Chromosomal instability at molecular level: CHROMOSOME STRUCTURE

A

Effect:

  • DICENTRIC
  • TELOMERE LENGTH
  • TRANSLOCATIONS
  • FUSIONS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Chromosomal instability at molecular level: SEQUENCE INTEGRITY

A

Effect:

  • BASEPAIR SUBSTITUTIONS
  • DELETIONS & INSERTIONS
  • METHYLATIONS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Chromosome Instability Causes: DEFECT IN CELL DIVISION

A

Effects:

  • Polyploidy
  • Aneuploidy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Chromosome Instability Causes: RECOMBINATION

A

Effect:

- Loss of heterozygosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Chromosome Instability Causes: DNA Replication

A

Effects:

  • Amplification
  • Deletions & Insertions
  • Basepair Substitutions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Chromosome Instability Causes: DNA Repair

A

Effects:

  • Translocations
  • Fusions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Chromosome Instability Causes: Dysregulation of Expression

A

Effect:

- Methylation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Chromosome Instability Causes: Attrition with Cell Proliferation

A

Effect:

- Telomere length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Chromosome Instability Causes

A
  • Defects in cell division
  • Recombination
  • DNA replication
  • DNA repair
  • Attrition with cell proliferation
  • Dysregulation of expression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Environmental DNA Damage

A

1) UV
2) X-rays
3) Heat generated hydrocarbons
4) Food additives
5) Job related exposures
6) Chemotherapeutic agents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

*Repair mechanisms for environmental DNA damage:

A

1) Nucleotide excision repair
2) Double-strand break repair
3) Interstrand crosslink repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Spontaneous DNA Damage

A

1) Hydrolysis
2) Reactive oxygen species
3) Nitric oxide
4) Methylation
5) Lipid peroxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

*Repair mechanisms for spontaneous DNA damage:

A

1) Base excision repair (&single-strand break repair)

2) Methyl transferase

17
Q

DNA repair: Why?

A
  • Repository of hereditary information
  • Blueprint for operation of individual cells
  • Only biomolecule that is repaired rather than replaced
18
Q

Effort dedicated to DNA repair

A
  • > 150 proteins dedicated to DNA repair
    ~3X as many proteins regulate the DNA damage response
    ~2% of the genome is dedicated to maintaining genome integrity
  • DNA repair proteins are “housekeeping proteins”
19
Q

Consequences of not repairing DNA damage (cell)

A
  • Errors in division
  • Chromosomal aberrations
  • Apoptosis
  • Senescence
  • Mutations
20
Q

Consequences of not repairing DNA damage (organism)

A
  • Xeroderma pigmentosum
  • Cockayne syndrome
  • Trichothiodystrophy
21
Q

Li-Fraumeni Syndrome

A
  • Caused by a mutation in p53
  • Osteosarcoma
  • Soft tissue sarcoma
  • Breast cancer
  • Brain tumors
  • Adrenocortical carcinoma
  • Leukemia
  • T cell lymphoma
  • Expression of constitutively active p53 protects against cancer but causes premature aging
22
Q

*General principles of DNA repair

A

1) Recognize the DNA Damage
- Endogenous DNA damage (small/subtle, co-evolved, dedicated enzymes)
- Environmental DNA damage (larger/alter DNA structure, rapid adaptation, generalized systems)
2) Remove the damage
3) Replace coding information
4) Restore the integrity of the phosphate backbone

23
Q

Defects in DNA glycosylases: Phenotype associated w/ defect in mice and humans

A
  • Mice: Defects in DNA glycosylases: none, but defects in core proteins = embryonic lethal
  • Humans: Polymorphisms related to cancer risk?
24
Q

Xeroderma Pigmentosum

A
  • Affected genome maintenance system: Nucleotide excision repair (NER)
  • Genome Instability: Point mutations
  • Phenotype: UV-induced skin cancer
25
Q

Cockayne Syndrome

A
  • Affected genome maintenance system: Transition-coupled Nucleotide excision repair (NER)
  • Genome Instability: Apoptosis
  • Phenotype: Premature Aging
26
Q

Trichothiodystrophy

A
  • Affected genome maintenance system: Transition-coupled Nucleotide excision repair (NER)
  • Genome Instability: Apoptosis
  • Phenotype: Premature Aging
27
Q

Ataxia Telanglectasia

A
  • Affected genome maintenance system: DSB-R and checkpoint
  • Genome Instability: Aberrations of 7 + 14 RRDS
  • Phenotype: Leukemias and lymphomas
28
Q

AT-like disorder

A
  • Affected genome maintenance system: DSB-R
  • Genome Instability: Aberrations of 7 + 14 RRDS
  • Phenotype: Ataxia
29
Q

Nijmegen breakage syndrome

A
  • Affected genome maintenance system: DSB-R and checkpoint
  • Genome Instability: Aberrations of 7 + 14 RRDS
  • Phenotype: Lymphomas
30
Q

Werner’s syndrome

A
  • Affected genome maintenance system: Telomere maintenance DSB-R
  • Genome Instability: Deletions, translocations, and fusions
  • Phenotype: Nonepithelial tumors
31
Q

Bloom Syndrome

A
  • Affected genome maintenance system: DSB-R (replication repair) and ICL-R
  • Genome Instability: Spontaneous SCEs
  • Phenotype: Epithelial tumors and leukemia
32
Q

Rothmund-Thompson Syndrome

A
  • Affected genome maintenance system: TCR
  • Genome Instability: Clonal translocations
  • Phenotype: Osteosarcoma and skin cancer
33
Q

Fanconi Anemia

A
  • Affected genome maintenance system: ICL-R
  • Genome Instability: Crosslink-induced radials and breaks
  • Phenotype: Solid tumors and leukemias
34
Q

Hereditary Nonpolyposis Colorectal Carcinoma

A
  • Affected genome maintenance system: MMR
  • Genome Instability: bp substitutions micro satellite instability
  • Phenotype: Colon cancer
35
Q

Mismatch repair in E. coli

A

1) Mismatches introduced during replication
2) MutS recognizes the mismatch
3) MutL stabilizes the DNA:protein complex
4) MutH discriminates between strands
5) MutH nicks near the new strand
6) UvrD unwinds the DNA from the nick
7) Exonuclease removes new strand
8) Pol3 replaces the patch
9) Ligase restores the backbone

36
Q

Microsatellite Instability

A
  • All eukaryotes contain tracts of DNA in which a single base or a small group of bases are tandemly repeated
  • Expansions of these tracts are associated with a number of human diseases
  • 1-3 base repeats particularly unstable in HNPCC
  • Instability in some sporadic CRC tumor cells
37
Q

MSI results form what

A
  • From slippage of the polymerase during DNA synthesis

Chromosomes Exam 2 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions