The Plasma Membrane
The plasma membrane consists of 40 percent of lipid molecules and 60 percent of proteins. It plays a very important role in living organisms, in which one of its main functions is to act as a barrier between the internal and the external environment of each cell. Not only that, but it also controls the chemical reactions of a cell. In 1935, Davson and Danielli suggested that 40 percent of the lipid molecules are arranged in a ‘lipid bilayer’. Each phospholipid molecule consists of a glycerol molecule linked to two long chain fatty acids and a phosphate group or phosphate head. The ‘lipid bilayer’ forms due to the hydrophobic and the hydrophilic nature of the phospholipid. The polar head or phosphate group is ‘hydrophilic’ or ‘water loving’ and the two fatty acid tails are hydrophobic, or ‘water hating’. The bilayer is therefore arranged in order for the fatty acids to exclude as much water as possible their structure. With improvements in technology (improvements in electron microscopy), a more detailed structure of the cell plasma membrane was laid out. The two scientists, in 1972, by the name of Singer and Nicolson, suggested that the membrane is a fluid structure and is always moving. They put forward the idea of the ‘ flui
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Some common words found in the essay are:
Substances CO, Singer Nicolson, Davson Danielli, , ATP Overall, surface membrane, lipid bilayer, cell surface, cell surface membrane, lipid molecules, main function, proteins span, plasma membrane, proteins span membrane, chemical reactions, span membrane, fatty acids, pass lipid bilayer, chemical reactions cell, percent lipid molecules,
Approximate Word count = 833
Approximate Pages = 3 (250 words per page double spaced)
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