Learning Outcomes in Listing:
i. Define and distinguish between necrosis and apoptosis.
ii. Understand the biological processes and implications of both forms of cell death.
iii. Identify examples of necrosis and apoptosis in biological systems.
Summary of Lesson:
Cells can die in different ways, with significant implications for the organism. Necrosis is a form of traumatic cell death that results from acute cellular injury, while apoptosis is a programmed, orderly process that occurs naturally in the body. This lesson will explore the mechanisms, causes, and effects of both necrosis and apoptosis.
i. Necrosis: Accidental Cell Death
Necrosis occurs when cells are exposed to extreme conditions such as toxins, infection, or trauma that cause irreversible damage to the cell membrane, leading to the cell's swelling and bursting.
Example: A heart attack can cause necrosis of heart muscle cells due to a lack of oxygen.
ii. Apoptosis: The Programmed Cell Death
Apoptosis is a tightly regulated process that involves the cell shrinking, condensing its chromatin, and then fragmenting into apoptotic bodies that are phagocytosed by other cells, without causing inflammation.
Example: Apoptosis occurs during the development of the fingers and toes in a fetus, where cells between the digits undergo apoptosis to separate them.
List of Important Questions for Self-Study:
i. How do necrosis and apoptosis differ in their effect on surrounding tissues?
ii. Why is apoptosis considered a normal part of the development and health of organisms?
iii. What are the consequences of disrupted apoptosis processes?
iv. How can necrosis be both harmful and a necessary response to acute tissue damage?
v. In what ways can understanding apoptosis contribute to medical advancements, such as cancer treatment?
Important Terminologies Used in Lesson:
Necrosis: A form of cell injury which results in the premature death of cells in living tissue by autolysis.
Apoptosis: A process of programmed cell death that occurs in multicellular organisms, characterized by a series of biochemical events.
Phagocytosis: The process by which a cell engulfs particles such as bacteria, other microorganisms, aged red blood cells, and apoptotic cells.
Chromatin: The material of which the chromosomes of organisms other than bacteria are composed, consisting of protein, RNA, and DNA.
