Chapter 10: Cell Growth and Division

Chapter 10: Cell Growth and Division

1. Cell Division

   • The process by which a cell divides into 2 new daughter cells

2. Reasons Cells Stay Small

   • #1: Small cells have a greater surfaces area to volume ratio than large cells. Large cells can more easily move nutrients and waste across their membranes to meet the demands of the cell.
   • #2: Every cell in an organism has the same amount of DNA. If the cell kept growing with the same amount of DNA it would be hard for that amount of DNA to control cell activities

3. Cyclins

   • Discovered in the 1980's
   • proteins that regulate the timing of the cell cycle in eukaryotes

4. Internal Regulators

   • proteins that respond to events occurring inside a cell.
   • Allows the cell cycle to proceed only when certain events have occurred

5. External Regulators

   • Proteins that respond to events outside the cell
   • Directs cells to speed up or to slow down the cell cycle

6. Apoptosis

   • Process of programmed cell death

7. Cancer

   • Cells divide uncontrollably
   • Cells don't respond to signals that regulate cell growth
   • Tumor
     • Mass of cancer cells
       • Benign Tumor
         • Doesn't spread to healthy tissue
       • Cancerous/Malignant Tumor
         • Spreads to surrounding tissue
   • Possible Causes of Cancer
     • Smoking or chewing tobacco
     • Radiation Exposure
     • Defective genes/viral infections
   • Possible Treatments
     • Removed by surgery
     • Beams of radiation
     • Chemotherapy

8. Cell Differentiation

   • The process of cells specializing into different types
   • EXAMPLE
     • Stem Cell
       • Erthtoid
       • Hematopoiesis
       • Myogenesis
       • ETC..