1. 10-3 Regulating the Cell Cycle How is the cell regulated? How are cancer cells different from other cells?

2. Controls on Cell Division Not all cells move through the cell cycle at the same speed Some cells don't divide at all once developed Some cells like skin and digestive tract cells divide throughout our entire life

3. Cell Cycle Regulators Proteins in cells regulate the timing of cell division in Eukaryotic cells – CYCLINS  Internal Regulators Proteins that only allow the cell cycle to continue if certain events have occurred Example: cell will not divide if the chromosomes have not been copied  External Regulators Respond to events outside the cell Growth regulators: embryonic development and healing

4. Uncontrolled Cell Growth Cancer- a bodies own cells do not respond to the signals that regulate growth Divide uncontrollably and form masses called Tumors.  Many have a defect in gene p53 that stops the cell cycle if the chromosomes haven't been copied correctly.