Gene Mutation Flashcards
What two genes control this rate of division in cells?
Proto-oncogenes - stimulate cell division
Tumour suppressor genes - slow cell division
Why do cells divide at a fairly constant rate?
To ensure that dead or worn out cells are replaced
What’s the roler he usual role of a proto-oncogene?
Stimulate cell division by a growth factor attaching to a receptor protein on cell surface membrane. Then via relay protein through cytoplasm it switches on genes for DNA replication
What happens when proto-oncogenes mutate?
They become oncogenes and effect in 2 ways
- receptor protein on cell surface membrane permanently activated so cell division switched on even without growth factor
- oncogene may code for growth factor that’s produced in excessive amounts stimulating cell division
What happens when tumour suppressor genes mutate?
Becomes inactivated, so it stops inhibiting cell division. The mutated cells formed are usually structurally and functionally different form normal cells
