Discuss two mechanisms that are present in cells to prevent damaged cells from reproducing and?

Question

and becoming a threat to life.

Answer 1

p53- This is an enzyme that checks the cell after the G1 phase to check that the DNA has been replicated properly. If it has, it then activates p21 which then acivates Cyclin Dependant Kinase that allows the cell to progress to S Phase. p53 is integral in preventing cancer and without it..cells quickly become cancerous. It causes destruction of cells that are beyond repair. (extra note...its discovery won a Nobel Prize a few years ago!)

Interferon alpha is a substance released by cells that are attacked and invaded by viruses. Its an automatic response that tells local cells and itself to shut down the metabolic machinery so the virus cannot take advantage. It also encourages white cells to come and deal with the problem.

A third point... in case you need it: When a virus attacks a cell, it changes the cells MHC class 1 peptide that is presented to T-cells that patrol. The changed MHC molecule sends alarm bells to the cytotoxic T-cell inspecting it, which prompts the T-cell to cause the infected cell to commit suicide and prevent further spread of the virus. The actual mechanism here pertains the expression of MHC class 1.