BIOL 4004 Lecture Notes - Lecture 1: Programmed Cell Death, Nuclear Membrane, Apoptosis
Document Summary
Apoptosis, or programmed cell death, is a vital process for multicellular organisms. It is required in certain stages of development. Also, apoptosis is needed to eliminate unwanted cells, such as those that have exceeded their normal lifespan, or those cells that may have the potential to cause cancer. In this section, we will consider the molecular mechanisms of apoptosis. Cells that undergo apoptosis have characteristic morphological and biochemical changes. The cells shrink and condense, the cytoskeleton collapses, the nuclear envelope disassembles, and the nuclear chromatin condenses and breaks up into fragments. The cell surface breaks up into membrane-enclosed fragments called apoptotic bodies. Biochemical changes cause apoptotic cells to be recognized by macrophages that engulf them before they can spill their contents. That way the cell is rapidly cleared away, without causing a damaging inflammatory response. Apoptosis is to be distinguished from necrosis, which may be caused by an acute insult, such as trauma or lack of blood supply.
