1 / 18

Cell Death, Cancer Cells and the Cell Cycle

Cell Death, Cancer Cells and the Cell Cycle. Life of Cell. The cell cycle regulates how long a cell lives. Cell Death: Necrosis and Apoptosis. Necrosis. death due to unexpected and accidental cell damage.

avari
Download Presentation

Cell Death, Cancer Cells and the Cell Cycle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cell Death, Cancer Cells and the Cell Cycle

  2. Life of Cell • The cell cycle regulates how long a cell lives. • Cell Death: Necrosis and Apoptosis

  3. Necrosis • death due to unexpected and accidental cell damage. • Caused by: toxins, radiation, trauma, lack of oxygen due to the blockage of blood flow. •  As necrotic cells begin to die, they swell – holes appear in the plasma membrane and intracellular materials spill out into the surrounding environment.

  4. Apoptosis • Also known as programmed cell death. • A way of removing unwanted cells. • Cells undergo a programmed sequence of events which lead to death of the cell. •  Occurs during growth and development of the organism • Part of normal cell aging, or as a response to cellular injury

  5. For example, when your body fights a viral infection, your body produces many cells to fight that infection. When the virus has been removed from your body, these cells are no longer needed and they are removed by apoptosis. Apoptosis also removes cells that have lost their ability to perform efficiently.

  6. Watch and Enjoy! • Video Clip

  7. Growing and Ageing • While you are growing, cell division adds to the total number of cells in your body. • When you have stopped growing, cell division continues. • Why? • Cells do not live forever. They can only divide a certain number of times until they receive a message or instructions to die. Cell division is necessary for cells to be replaced after they die. • In your body, 3 billion cells die every minute.

  8. Growing and Ageing • We undergo cell division as part of regeneration, a process essential for repairing damaged tissue. • Why do we age? • It is believed we age because as cells die, they are not replaced or not replaced as quickly. • This results in changes to the structure and function of major body systems.

  9. Cancer • In a normal cell, instructions in the DNA control the rate of cell division. • If the genetic material goes wrong, the cell will destroy itself.

  10. Cancer • When a cell’s DNA is changed, that is called a mutation. Viruses, UV light and cigarette smoke can cause mutations. Some cancer causing mutations are inherited. When changes in the DNA result in the cell losing its control over cell division, it is called a cancer cell.

  11. Cancer • A normal cell will live for between 50 and 60 cellular divisions. • Cancer cells are “immortal” because they never stop dividing. • A normal cell will undergo apoptosis if it is damaged genetically, whereas a cancer cell will continue to divide. • Cancer Cell Video Clip • Clip #2

  12. Tumours • Video Clip • Benign: tumour cells remain at their original site. • Malignant: some tumour cells send out signals that tell the body to produce a new blood vessel at the tumour site.

  13. Tumours • These cells not only have a food and oxygen supply, they also have an avenue for escape to a new part of the body - through the new blood vessel and into bloodstream. • Cells can break away from the tumour and begin to spread to surrounding tissues and start new tumours = metastasis. • Tumour Video Clip

  14. A B C Ds • A = asymmetry • B = borders are irregular • C = color • D = diameter

More Related