Question

What is an ester linkage in lipids?

Answer 1

Lipids are insoluble inorganic molecules that are not soluble in polar solvents such as water. Lipids consist of fats and other forms of lipids such as phospholipids, sphingolipids, glycolipids, and steroids such as cholesterol.

Complete answer:
Esterification is a process in which a carbonyl group is attached with alcohol with a release of a water molecule. The bond formed between both organic molecules is called an ester linkage. A simple fatty acid monomer of a lipid consists of an even number of hydrocarbon chains joined with single bonds. A typical structure of lipid consists of a polar end and a nonpolar long fatty acid chain. Another form of lipid, a triacylglycerol (TAG), consists of a glycerol molecule and three long fatty acid chains. These long fatty acid chains are attached with the glycerol molecule through esterification and release three water molecules. The process through which they are formed is known as dehydration. The ester linkage is formed between the oxygen molecules of glycerol and the hydroxyl molecules of fatty acids. The formation of ester linkage is an endothermic reaction. What a TAG is hydrolyzed, it releases free fatty acid chains, monoglycerides, diglycerides, and glucose molecules.

Note:
Lipids are very essential biomolecules for organisms. They are present in the cell membranes of all eukaryotes as lipid bilayers to provide rigidity and structure to cells. They are also essential in storing energy within the cells, cell to cell communication, and provide a semi-permeable barrier for intercellular and intracellular transport of molecules.