Here's why:
* Lipids are a diverse group of molecules, but the most common type is triglycerides.
* Triglycerides are composed of a glycerol molecule (a three-carbon alcohol) and three fatty acid molecules.
* The fatty acids are attached to the glycerol molecule through ester bonds. An ester bond forms when a carboxylic acid (the fatty acid) reacts with an alcohol (glycerol). This reaction releases a water molecule.
In summary: The ester bond is the crucial link that holds together the building blocks of triglycerides, the most common type of lipid.
