Welcome to Class 12-7 & Turn in 4 Biomolecule paper 2. Work on STAAR Review Session 2 # Regulating Cell Cycle Note 4. Research diseases 5. HF: Assigned Vocab 6. Reminder: - Quiz over cell cycle next class! - SEM EXAM next week! - Sem Exam Study Guide on webpage!

Regulating the Cell Cycle Why is this even important?

Can we cure cancer?

If we want to cure cancer.... We must understand what causes is. That means understanding the cell cycle. Cancer is an illness where Cell Growth Uncontrollably or grow without stopping

Cancer: Uncontrolled Cell Growth Cancer cells don’t respond to normal regulatory signals. Cell cycle is disrupted. Cells grow and divide uncontrollably. tumor blood vessel

Cancer Formation: A Closer Look 1.A cell begins to divide abnormally. 2.Cells produce a tumor and start to displace normal cells and tissues. 3.Cancer cells move to other parts of the body.

What Causes Cancer? In all cancers, control over has broken down. Cancer results from a defect in genes that control cell growth and division. the cell cycle

Cancer Incidence

Surgery to remove localized tumor Radiation to destroy cancer cell DNA Chemotherapy to kill cancer cells or slow their growth Treatments for Cancer

What controls cell division? Cell cycle regulators Cyclin Internal regulators External regulators Check out this game over the regulation of the Cell Cycle at l Also this animation describe the CHECKPOINTS that occur during the cell cycleanimation

Checkpoints There are strict checkpoints in the cell cycle to ensure that each stage does not start before the last one has finished. Other checkpoints prevent cells dividing when their DNA is damaged - either allowing time to repair the damage or, if the DNA is too damaged, causing cell death.

Apoptosis A process of programmed cell death Important role in structuring tissues during growth and development Cell undergoes a series of controlled steps for self- destruction. A process of programmed cell death Important role in structuring tissues during growth and development Cell undergoes a series of controlled steps for self- destruction.

Cancer = uncontrolled cell growth When control of the cell cycle fails, cells begin to divide uncontrollably, resulting in masses and failure of the cells to perform their normal functions. This condition is called cancer. Causes: environmental, genetic, viruses *Viruses such as HPV, also called human papillomavirus are known to be linked to cervical cancer.

Cells divide at different rates, depending on the cell type --Nerve and muscle cells usually stop dividing once developed --Skin cells divide frequently as skin is being replaced constantly

Healing a Bone Cells at the edge of an injury are stimulated to divide rapidly. As an injury heals, the rate of cell division slows. new bone cells

The Discovery of Cyclins Scientists found a protein in a cell undergoing mitosis. They injected the protein into a non-dividing cell. A mitotic spindle started to form. Cyclins: proteins that regulate the cell cycle

Regulatory Proteins Internal regulators: respond to events inside the cell let cell cycle proceed only when certain steps have already happened External regulators: respond to events outside the cell growth factors: wound healing and embryonic development others cause cells to stop or slow their cell cycles.

Apoptosis A process of programmed cell death Important role in structuring tissues during growth and development Cell undergoes a series of controlled steps for self- destruction. A process of programmed cell death Important role in structuring tissues during growth and development Cell undergoes a series of controlled steps for self- destruction.

Student Worksheet Answers