AS Biology Core Principles : AS Biology Core Principles Lipids Visit www.worldofteaching.com
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Aims : Aims Elements of lipids
Structure of glycerol & fatty acids
Condensation reactions to form triglycerides
Phospholipids
Introduction to lipids : Introduction to lipids
Introduction to lipids : Introduction to lipids Lipids contain the elements carbon, hydrogen and oxygen.
They have numerous functions, primarily energy stores in animals and plants.
Lipids consist of two types of molecules - glycerol & fatty acids.
Glycerol : Glycerol A molecule of glycerol is made up of three carbon atoms.
Each of these has a hydroxyl group attached to it.
Hydrogen atoms occupy the remaining positions.
Fatty Acids : Fatty Acids
Fatty Acids : Fatty Acids A single fatty acid molecule contains an acid (COOH) group attached to a hydrocarbon chain.
Hydrocarbon usually denoted by the letter ’R’.
Saturated = If every carbon atom in the chain is joined by a single C-C bond.
Unsaturated = at least one C=C bond.
Polyunsaturated = many double bonds.
Most animal fats are saturated while most plant fats are unsaturated.
Triglycerides : Triglycerides
Triglycerides : Triglycerides A triglyceride molecule is made of a glycerol molecule and three fatty acids.
The molecules join together through the process of condensation losing a molecule of water each time a link is made.
The link between the glycerol molecule & each fatty acid is an ‘Ester Link’.
The fatty acids in a lipid molecule can differ in length and can be saturated or unsaturated.
Triglycerides : Triglycerides
Phospholipids : Phospholipids In phospholipids one of the fatty acids of a triglyceride is substituted by a phosphate group.
Phospholipids : Phospholipids
Phospholipids : Phospholipids
Lipids & water : Lipids & water Triglycerides and phospholipids have hydrophobic and hydrophilic groups.
What does this mean?
To what use is this feature put in biology?
More Info : More Info To make further notes on Lipids :
Pages 11 & 12 in Collins
Pages 69 - 71 Roberts
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