1.3 Membrane Structure

Question	Answer
Define the term "Plasma membrane":	A biological membrane which separates the interior of a cell with the external environment.
In a single phospholipid molecule, which part is hydrophilic and which part is hydrophobic?	The Phosphate head is polar- hydrophilic. The fatty acid tails are non-polar- hydrophobic.
Summaries how hydrophobic and hydrophilic properties of the phospholipid bilayer allow a membrane to maintain its structure:	When put into water, phospholipids will self-organise to keep their heads 'wet' and their tails 'dry'. A phospholipid bilayer is one way that the tails can be removed from the water.
Outline the structure of the Davson-Danielli model of the cell membrane:	Is a protein-lipid sandwich. Lipid bilayer is composed of phospholipids. Proteins coat outer surface. Proteins do not spread through the lipid bilayer.
What did the Davson-Danielli model help explain?	Despite being very thin, membranes are effective barriers to the movement of certain substances.

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	Created by Ines Thorpe over 6 years ago