BIOL 3070 Final: final pt 4/4 study sheet

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Protooncogenes encode proteins that stimulate cell division (under appropriate circumstances). genes in normal cells that encode various types of proteins that stimulate cell division. In cancer, these genes are altered to become oncogenes, and stimulate cell to progress to cancerous state. e. g. ras. Learning objectives (los): describe key attributes of cancer. Cancer cells have several features that distinguish them from normal cells- they have no contact inhibitions. Normal cells divide until they bump against each other and then stop, but cancer ignores the signal and continue to divide, piling on top of one another. Cancer cells divide indefinitely normal cells can divide a finite number of times cancer cells never lose their ability to divide and continue to do so, normal cells have a limit. Metastasis- cells grow as benign tumour in epithelium, breaks through basal lamina, invades capillary. = travels through blood stream (less than 1 in 1000 cells will survive to form metastasis).