[OLD] DNA - Cancer Flashcards
Cell division is a natural process needed for…
the growth, repair and replacement of cells in our body
What is cell division regulated by?
Our DNA
What happens to DNA throughout a person’s life?
It accumulates damage
What makes a healthy cell to make it a cancer cell?
A certain amount of damage to its DNA
How do cancer cells form a tumour?
They divide out of control
Why do cancer cells not die?
The genes that repair DNA and cause faulty cells to self-destruct are damaged
What happens when a tumour reaches a certain size?
Metastasis - cancer cells break off and spread through the blood to another part of the body
Why does the chance of survival greatly increase with early detection and treatment?
Once a cancer has metastasised it is harder to treat
Give 4 examples of carcinogens
Smoking (cigarette smoke)
Benzine (by-product of industrial products)
UV radiation
X rays
When do tumours become harder to cut out?
Once they have established a blood supply
What is apoptosis?
That every cell is programmed to die at some point
describe how some treatments for cancer are designed to control the rate of cell division in tumour cells
by disrupting the cell cycle, killing the tumour cells.
these treatments don’t distinguish tumour cells form normal cells though, so they also kill normal body cells that are dividing. however tumour cells divide much more frequently than normal cells, so the treatments are more likely to kill tumour cells.
give an example of a cancer treatment that targets G1, and describe how it works
chemotherapy - some chemical drugs prevent the synthesis of enzymes needed for DNA replication. if these aren’t produced, the cell is unable to enter the synthesis phase, disrupting the cell cycle and forcing the cell to kill itself
give an example of a cancer treatment that targets S phase, and describe how it works
Radiation (as well as some drugs) damage DNA. At several points in the cell cycle (including just before and during the S phase) the DNA in the cell is checked for damage. If severe damage is detected, the cell will kill itself - preventing further tumour growth.
