Cancer cell division Flashcards
Cells are not meant to grow indefinitely. The cell cycle
_______ how long a cell lives.
regulates
Necrosis
this is the premature death of a cell due to injury
ex: burns, scrapes, gangrene
Apoptosis
this is the programmed death of a cell that is no longer useful → normal process to aid in survival of organisms
ex: loss of tail in a tadpole, loss of webbing between fingers and toes in a human fetus
Apoptosis Protects Us!
In humans, as many as 1011 cells die each day and are replaced by other cells. In fact, the mass of cells we lose each year through normal cell death is close to our entire body weight!
Cell Cycle Checkpoints
The cell cycle has various checkpoints to ensure our cells are progressing as they should. If damage is found, the cell tries to repair it. If it can’t be repaired, the cell undergoes apoptosis.
What is Cancer?
Cancer is a disease that occurs when there is a loss of balance between cell division and cell death. The cells that should have died, divide uncontrollably instead.
Tumors
Uncontrolled cell division gives rise to a rapidly growing mass of cells that form a lump or tumor.
Benign:
The tumor does not affect the surrounding tissues. Benign tumors are not cancerous.
Malignant:
The tumor interferes with the functioning of surrounding cells. Malignant tumors are cancerous.
Metastasis
occurs when cancer cells break away from the original tumor and settle in a new location in the body.
Metastasis is one of the reasons why cancer is so dangerous!
Cancer & Mutations
Cancer results from a mutation → a random change in the DNA. This mutation causes a cell to behave abnormally.
Causes of Cancer
- Some mutations are caused by environmental factors called carcinogens.
Some examples of carcinogens are: - cigarette smoke
- radiation from x-rays
- UV radiation from the sun and tanning beds
- some viruses such as HPV and hepatitis B
- certain chemicals in plastics → bisphenol A (BPA)
- food additives
