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Biology
Chemistry
Science
Human biology
Biology
Biology
Science (applied)
Chemistry
Biology
Every cell contains high levels of inorganic phosphate ions (-PO43-). Sometimes one of the fatty acidfatty acid
Large molecule consisting of a carboxylic acid (RCOOH) with the 'R' being a long unbranched hydrocarbon chain.
s in a triglyceride is replaced by a phosphate groupphosphate group
A molecule containing phosphorus and oxygen.
to form a phospholipidphospholipid
A lipid molecule with a hydrophilic region around the ionic phosphate group and a long hydrophobic hydrocarbon tail that forms a bilayer in aqueous solutions.
. Phospholipid molecules have a hydrophilichydrophilic
Molecules that absorb or dissolve in water - usually polar molecules.
region around the phosphate group which is soluble in water and hydrophobichydrophobic
Insoluble in water, repel water.
regions around the fatty acids which are not soluble and repel water. This is a key element in the structure of cell membranemembrane
A thin, flexible sheet-like structure that acts as a lining or a boundary in an organism.
s and so in the nature of life itself.
Structure of a phospholipidphospholipid
A lipid molecule with a hydrophilic region around the ionic phosphate group and a long hydrophobic hydrocarbon tail that forms a bilayer in aqueous solutions.
– the hydrophilichydrophilic
Molecules that absorb or dissolve in water - usually polar molecules.
and hydrophobichydrophobic
Insoluble in water, repel water.
regions of the molecule have a major effect on the structure of cell membranemembrane
A thin, flexible sheet-like structure that acts as a lining or a boundary in an organism.
s
Waxes are lipids made up of very long chain fatty acidfatty acid
Large molecule consisting of a carboxylic acid (RCOOH) with the 'R' being a long unbranched hydrocarbon chain.
s joined to alcohols by ester bonds that are insoluble in water but soluble in organic polar solvents. The big difference between waxes and triglyceridestriglycerides
The most common lipid found in nature and consists of a single glycerol molecule bonded to three fatty acids.
is that in waxes there is only one fatty acid joined to a single alcohol, because alcohols only have one available hydroxyl group, unlike glycerol which had three. Waxes on the surface of leaves and insect cuticles, along with oils on feathers and fur, form a water-proof layer which enables the organisms to survive in their environments.
Steroids are insoluble in water but otherwise are not typical lipids – they are made up of large numbers of carbon atoms arranged in complex ring structures. They are very important in biological systems as hormones.
Other lipids or lipid-derived molecules which are important in biological systems include:
For years the scientific evidence suggested saturated fats in the diet increased the risk of coronary heart disease. More recently, scientists have thrown doubt on this.
Investigate this using a variety of sources (for example the internet, scientific journals or interviews with experts if you can). Then write two articles in different styles:
