Regulating The Cell Cycle
Warm Up – The Cell Cycle The cell spends 80% of the time in _______________ and 20% of the time in ________________ What are the steps in mitosis?
Key Concept How is the cell cycle regulated? How do cells know when to divide? How do you heal when you break a bone?
Regulate the Cell Cycle Cyclin: A protein that regulates the cell cycle Tells the cell when to begin mitosis
Growth Factors Growth factors stimulate the growth and division of cells When is this important?
How Does a Cell Die? 1. Accident or injury 2. Apoptosis: Programmed cell death
What is Cancer? How have we been affected by cancer? How are cancer cells different from other cells? Why doesn’t everyone get cancer?
Cancer Cancer: Uncontrollable cell growth Cancer cells don’t respond to signals that regulate growth of cells Tumor: Mass of cells that divide uncontrollably
What Causes Cancer? Defects in genes that regulate cell growth and division. Example: Defect in gene p53, which normally stops the cell cycle until all chromosomes are properly replicated.
How Cancers Spread: Metastasis Cancerous cells lose control and continue to grow & divide, producing tumors which can metastasize (spread to other parts of the body)
Think & Apply… How are cancer cells different from normal cells? When researchers develop drugs, what characteristic of cancer cells do you think they target?