Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
The Cell Cycle and Cancer • The Stages of the Cell Cycle There are several factors that regulate the cell cycle and assure a cell divides correctly. 1.Before a cell divides, the DNA is replicated in S phase, and checked to make sure it has replicated correctly. If DNA does not copy itself correctly, a gene mutation occurs. DNA replication animation:click on DNA picture 2. Chemical Signals programmed into the DNA tell a cell when to start and stop dividing. (Target cells animation: click on go sign) 3. Neighboring cells communicate with dividing cells to regulate their growth also. Cancer is a disease of the cell cycle. Some of the body’s cells divide uncontrollably and tumors form. Tumor in Colon Tumors in Liver DNA mutations that occur in S phase disrupt the cell cycle when DNA is damaged or not copied correctly. Mutations may be caused by: 1. radiation 2. smoking 3. Pollutants 4. chemicals 5. viruses While normal cells will stop dividing if there is a mutation in the DNA, cancer cells will continue to divide with mutation. Due to DNA mutations, cancer cells ignore the chemical signals that start and stop the cell cycle. https://www.youtube.com/watch?v=IeUANx FVXKc Due to DNA mutations, cancer cells cannot communicate with neighboring cells. Cells continue to grow and form tumors. Skin cancer SUMMARY Normal Cell Division 1. DNA is replicated properly. 2. Chemical signals start and stop the cell cycle. 3. Cells communicate with each other so they don’t become overcrowded. Cancer Cells 1. Mutations occur in the DNA when it is replicated. 2. Chemical signals that start and stop the cell cycle are ignored. 3. Cells do not communicate with each other and tumors form. Treating Cancers Currently, most cancers are treated by either removing the tumor (biopsy), or trying to kill the cancer cells through: • Radiation Therapy • Chemotherapy (Unfortunately, these treatments are not specific to cancer cells. They also kill healthy cells, causing the patient to lose hair, become nauseous, and become extremely weak.)