 of an Acylglycerol, a Phospholipid, and a Terpene.png)
Learning Objectives:
i. Describe the steps involved in the esterification of fatty acids and glycerol to form an acylglycerol.
ii. Explain the steps involved in the esterification of fatty acids and phosphatidic acid to form a phospholipid.
iii. Describe the steps involved in the polymerization of isoprene units to form a terpene.
Esterification of Fatty Acids and Glycerol to Form an Acylglycerol
The esterification of fatty acids and glycerol to form an acylglycerol is a condensation reaction. In a condensation reaction, two molecules are combined and a molecule of water is lost.
The steps involved in the esterification of fatty acids and glycerol to form an acylglycerol are as follows:
i. A fatty acid molecule and a glycerol molecule are combined.
ii. A proton is transferred from the hydroxyl group of the glycerol molecule to the carbonyl carbon atom of the fatty acid molecule.
iii. This creates a water molecule, which is lost.
iv. The remaining two molecules are bonded together by an ester linkage.
The following equation shows the esterification of fatty acids and glycerol to form an acylglycerol:
Fatty acid + Glycerol → Acylglycerol + Water
Esterification of Fatty Acids and Phosphatidic Acid to Form a Phospholipid
The esterification of fatty acids and phosphatidic acid to form a phospholipid is also a condensation reaction.
The steps involved in the esterification of fatty acids and phosphatidic acid to form a phospholipid are as follows:
i. A fatty acid molecule and a phosphatidic acid molecule are combined.
ii. A proton is transferred from the hydroxyl group of the phosphatidic acid molecule to the carbonyl carbon atom of the fatty acid molecule.
iii. This creates a water molecule, which is lost.
iv. The remaining two molecules are bonded together by an ester linkage.
The following equation shows the esterification of fatty acids and phosphatidic acid to form a phospholipid:
Fatty acid + Phosphatidic acid → Phospholipid + Water
Polymerization of Isoprene Units to Form a Terpene
Terpenes are formed by the polymerization of isoprene units. Polymerization is the process of combining multiple monomers to form a polymer.
The steps involved in the polymerization of isoprene units to form a terpene are as follows:
i. Two or more isoprene units are combined.
ii. The carbon atoms in the isoprene units are rearranged to form a terpene molecule.
The following equation shows the polymerization of isoprene units to form a terpene:
Isoprene units → Terpene
Breaking of Acylglycerols, Phospholipids, and Terpenes
- Acylglycerols, phospholipids, and terpenes can all be broken down by hydrolysis reactions. Hydrolysis is the process of splitting a molecule into two or more smaller molecules by using water.
- The hydrolysis of acylglycerols, phospholipids, and terpenes is catalyzed by enzymes. Enzymes are proteins that speed up chemical reactions.
The following equations show the hydrolysis of an acylglycerol, a phospholipid, and a terpene:
Acylglycerol + Water → Glycerol + Fatty acids
Phospholipid + Water → Phosphatidic acid + Fatty acid
Terpene + Water → Isoprene units
Acylglycerols, phospholipids, and terpenes are all important classes of lipids. Acylglycerols are used to store energy, phospholipids are the main component of cell membranes, and terpenes have a variety of biological functions, including fragrance, defense, and communication.
The synthesis and breakdown of acylglycerols, phospholipids, and terpenes are both important processes in living organisms. The synthesis of these lipids is required for the construction and maintenance of cell membranes and other cellular structures. The breakdown of these lipids provides energy and other resources for cells.
