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The Regulation of Cell Death: APOPTOSIS. Presented by: Jesse Kemp. Introduction and Overview. Death Due to External Source or Injury vs. Death by Committing Suicide Why Is There a Need For This Type of Pathway? Causes of Apoptosis Mechanism of Apoptosis.
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The Regulation of Cell Death: APOPTOSIS Presented by: Jesse Kemp
Introduction and Overview • Death Due to External Source or Injury vs. Death by Committing Suicide • Why Is There a Need For This Type of Pathway? • Causes of Apoptosis • Mechanism of Apoptosis
Death by External Source or Injury • Toxin Damage • Mechanical Damage • Uncontrolled Swelling • Leakage of Cell Contents • Resulting Inflammation of Surrounding Tissue
Death by Committing Suicide While committing suicide cells: • Shrink • Chromatin Degraded • Mitochondria Break Down • Break into Membrane-bound Fragments • Phosphatidylserine Exposed • Phagocytic Receptors • Inflammation Inhibition
Purpose for this Pathway! Apoptosis is needed for: • Proper Development of the Organism ex) Formation of Fingers and Toes ex) Resorption of the Tadpole Tail during Metamorphosis • Destruction of Cells that Pose a Potential Threat to the Organism ex) Cells Infected with Viruses ex) Cells of the Immune System ex) Cancerous Cells
Balancing Act Within Every Organism, there is a Continual Battle Fought Between the Withdraw of Positive Signals and the Receipt of Negative Signals • Positive Signals • Negative Signals
Mechanism of Apoptosis • 3 Different Pathways Internal (Mitochondrial) Pathway External (Death Receptor) Pathway Non-Caspase Pathway
External Pathway (Death Receptor) Fas and TNF Receptor Death Activator (FasL) Caspase 8 Phagocytosis Ex) Cytotoxic T Cells Non-Caspase Pathway AIF Released from Mitochondria Migration to the Nucleus DNA Binding Alternate Pathways
Conclusion • Sources of Cell Death • Need for the Apoptosis Pathways • Causes of Apoptosis • Mechanisms of Apoptosis