Cell Membrane Presentation
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Transcript of Cell Membrane Presentation
2 Green
History
1855 - C. Naegeli and C. Cramer describe cell membrane as barrier essential to explain osmosis in plant cells
History (Continued)
1972 – The fluid mosaic model was created by S. J. Singer and Garth Nicolson, and stated that cell membranes can be considered as a two-dimensional liquid where all lipid and protein molecules diffuse freely
Structure (Continued)Primarily lipids and proteinsUnsaturated/Saturated changes
rigidityPolar, usually rejects ions,
hormones, ion channelsProteins stretch through,
integral proteinsCellular
communication/recognition
LocationIn an animal cell,
outermost layer
In a plant cell, just inside cell wall
Present in both
FunctionThe lipid bilayer provides rigidity, maintaining
the shape of the cell
Materials that can be dissolved in water pass through the membrane via osmosis
Other materials rely on ion channels to move through
InteractionsWorks with the cytoskeleton, structure
Ribosomes produce proteins that are then inserted into a lipid bilayer of their own by the endoplasmic reticulum and transported to the cell membrane by a vesicle, where both are absorbed into the cell membrane
Effi ciency and Effectiveness
Seperates the cytoplasm from the extracellular environment
Allows materials to be transported across it
If the cell membrane were not there, it wouldn’t make sense to call it a cell, more of a soup that flows around mixing with its surroundings and spreading out.
Sourceshttp://www.usoe.k12.ut.us/CURR/science/sciber
00/7th/cells/sciber/membrane.htm June 15, 2000
http://www.cellsalive.com/cells/cell_model.htm, 2006
http://en.wikipedia.org/wiki/Cell_membrane, 14 November 2009
http://www.whatislife.com/education/fact/history_table.html
, November 8, 2009