Cell determination and cell senescence Flashcards
What mechanisms are there for memory in cell determination? [2 marks]
- Chromatin remodelling
- Positive feedback
What is MITF? [1 mark]
Master gene regulator for melanocytes
What is melanocortin 1 receptor (MC1R)? [1 mark]
Receptor for melanocyte stimuating hormone (melanocortin 1)
What is a syndrome caused by one mutated copy of the MITF gene? [1 mark]
Waardenburg syndrome
What are myogenic factors? [2 marks]
- Interacting master gene regulators in skeletal muscle differentiation
- MYOD1, MYF5, MYOG and MRF4
What can inhibitors of differentiation 1 (ID1) bind to?
E proteins
What are E proteins? [1 mark]
Widely expressed transcription proteins
What is cell senescence? [1 mark]
Permanent cell growth arrest following extended cell proliferation
What morphological changes occur during senescence? [3 marks]
- Lamin around nucleus is lost
- cells become large and flat
- nucleolus is prominent
What enzyme maintains telomere length? [1 mark]
Telomerase (protein rna complex)
How does telomerase replicate telomeric DNA? [2 marks]
- Rveerse transcribes TTAGGG from it’s own RNA sequence
- enzyme used is telomerase reverse transcriptase
What cell types have telomerase activity? [2 marks]
- Gametes
- Cancer cell lines
How does p53 affect the cell cycle? [1 mark]
Inhibits the cell cycle when DNA is damaged
When is p16 triggered? [1 mark]
When telomeres shorten
