Lipids sheet-3 - n/a PDF

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Lipids Lipids have the following elements present Lipids can be categorised into 2 main groups: fats and oils. Triglycerides are made up of fatty acids and glycerol. The diagram below shows a triglyceride:

The bond between a fatty acid and a glycerol is an ester bond. Triglycerides are synthesised (formed) during condensation reactions. The triglycerides are then broken down into fatty acids and glycerol during hydrolysis, a process which uses water. Now lets take a look at the chains, the fatty acid chains. If these chains are described as saturated, they have no C=C bonds. If they are unsaturated, then there are C=C bonds present. The diagrams below show a saturated fatty acid chain and an unsaturated fatty acid chain.

The diagram below shows a phospholipid molecule:

Phospholipids are used in the cell surface membrane. They are particularly useful due to their properties. Remember how phospholipids have a hydrophillic (water loving) head and a hydrophobic (water hating) tail. The hydrophillic heads are always facing the external environment (ie. The cytoplasm inside the cell and the surrounding fluid around the cell) which contains lots of water. Meanwhile, the hydrophobic tails are facing

eachother inside the membrane where there is no water. The diagram shows how these phospholipid molecules are arranged in the membrane:...