Cancer and Cell Death Notes

Cancer and Cell Death

Checkpoints in the Cell Cycle

Researchers have discovered three main checkpoints where the cell assesses its growth before proceeding with cell division. Cell division is halted if:

  • There are insufficient nutrients to support cell growth.

  • The DNA has not been replicated.

  • The DNA is damaged.

Cell Death

Necrosis

  • Cell death due to external factors.

  • Examples include toxins, infections, and trauma.

Apoptosis

  • Controlled or programmed cell death.

  • Example: White blood cells undergo apoptosis when they are no longer needed after fighting infections.

Cancer

Genetic mutations can cause cells to undergo abnormal cell division.

  • Instead of undergoing apoptosis, these cells divide uncontrollably.

  • Rapid cell division leads to a buildup of cells, forming a tumor.

    • This reduces the effectiveness of the surrounding tissue.

Changes to these abnormal cells in the tumor can lead to cancer.

  • Cancer cells may invade and destroy neighboring cells.

  • They may stimulate other cells to start replicating uncontrollably, spreading the cancer and causing different types of cancer.

Benign vs. Malignant Tumors

Benign Tumor

  • The cells of the tumor stay together and do not seriously affect the surrounding tissue.

  • Cells in a benign tumor are not cancerous.

Malignant Tumor

  • A mass of cells that interferes with the function of neighboring cells and tissues.

  • The cells in a malignant tumor are cancerous.

  • Cancer cells can move to other locations in the body through the circulatory and lymphatic systems via a process called metastasis.

Treatment Options

★ Radiation therapy: Uses high-energy rays to kill cancer cells. A large machine directs radiation at the body.

★ Chemotherapy: Uses anti-cancer drugs to kill cancer cells (also kills healthy cells).

★ Surgery: Physical removal of all cancerous tissue.

Homework

  • Read Pages 42 – 44, 51

  • Answer Question #6 (p. 45) and Question #30 (p. 53)