BIOL 303 Lecture Notes - Lecture 3: Lipid Bilayer, Amphiphile, Glycerophospholipid
Chapter 10
• Recall the major lipids that make up bilayer membranes and their structural
characteristics (Chapter 10, slides 5-9).
• Lipids are amphiphilic molecules with a hydrophilic head and a hydrophobic tail.
• Lipid bilayer is approximately 5nm.
• Phospholipids make up about 50% of the cell membranes and the rest is proteins
and carbohydrates.
• The major phospholipid in mammalian membranes are phosphoglycerides.
• Glycerol backbone linked through ester bonds with (usually two) fatty acid
tails.
• All have a kink in one of the fatty acid tails due to a double bond that is cis.
This prevents the stacking of phospholipids. Temp can influence.
• Other lipids include Sphingolipids.
• Sphingosine backbone linked to long acyl (CH) chains and/or fatty acid,
and sterols.
• Cholesterol is an abundant sterol in cell membranes.
• Recognize the features of lipid structure that produce its self-’healing’ and fluid character
(Chapter 10, slides 10-15).
• It is energetically favorable to form the bilayer due to the hydrophobic tails, so the
tails come together quickly to “heal” itself.
• The membrane is fluid and plastic, so it easily reseals itself and moves very
easily.
• Two-dimensional fluid with 3D movement.
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