IB Biology - Cell Membrane Structure
Chapter 1.3 - Membrane Structure
Components of Cell Membrane
The cell membrane is constituted by 3 major components, including phospholipid, cholesterol and protein.
Amphipathic compound possesses both hydrophilic (water-loving, polar) and lipophilic (also known as hydrophobic, water-hating, fat-loving, non polar) properties.
The Development of cell membrane theory
How do the 3 components construct the cell membrane? This question bewildered the scientists for half of a century. No microscope can reveal the detail of the cell membrane, thus the scientist achieved the cell membrane theory by try and error.
This “fat sandwich model” widely accepted until the Singer and Nicolson abolished this model by “fluid mosaic model” in 1972
Singer and Nicolson found out the proteins in the cell membrane are not universally the same, different cells have different proteins
Moreover, the image from freeze-etching (IB Biology chapter 1.1) reveals the surface of the cell membrane is rough, meaning there are proteins intersecting in the cell membrane but not laying smoothly on the membrane
Fluid Mosaic Model
Why it is called the fluid mosaic model?
Drawing of the Model
In this IB biology topic, you need to understand
~That is the end of today topics~
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Written by Queenie l IBDP Biology Specialist @ TUTTEE
1. Wikimedia Commons, https://commons.wikimedia.org/wiki/File:0302_Phospholipid_Bilayer.jpg
2. Dict.Eudic.Net., https://dict.eudic.net/dicts/en/phospholipid
3. Open Textbook of Hong Kong, http://www.opentextbooks.org.hk/ditatopic/34628
4. Slideplayer, https://slideplayer.com/slide/4217868/
5. Youtube, https://www.youtube.com/watch?v=JVVRiPE38Uc
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