1.2.1 Lipids

Main Types of Lipids:

1. Triglycerides:

• Structure: A triglyceride is made up of one glycerol molecule and three fatty acids. These molecules are joined by ester bonds formed in a condensation reaction.
• Function: Triglycerides are used primarily for long-term energy storage in both animals and plants. They provide more energy per gram than carbohydrates or proteins because of their high proportion of carbon-hydrogen bonds.
• Properties:
• They are insoluble in water, so they do not affect the water potential of cells.
• They are a compact storage molecule, allowing large amounts of energy to be stored in a small space.
• Triglycerides can also act as an insulating layer in animals, helping to maintain body temperature.

2. Phospholipids:

• Structure: Phospholipids consist of a glycerol molecule attached to two fatty acids and a phosphate group. The phosphate group makes the head of the phospholipid hydrophilic (attracted to water), while the fatty acid tails are hydrophobic (repelled by water).
• Function: Phospholipids are key components of cell membranes, forming the phospholipid bilayer. This bilayer structure allows cells to control what enters and exits, maintaining the internal environment of the cell.