Lipids are a heterogeneous group of organic compounds that are insoluble in water but soluble in organic solvents. They are an important source of energy and play a vital role in cellular structure and function.
Fatty acids are long-chain hydrocarbons with a terminal carboxyl group. They may be saturated or unsaturated depending on the presence of double bonds.
Triglycerides are esters of glycerol with three fatty acid molecules. They serve as the major storage form of energy in the body.
Phospholipids are essential components of cell membranes. They consist of glycerol, fatty acids, phosphate, and a nitrogenous base.
Cholesterol is a sterol lipid present in animal tissues. It is a precursor for steroid hormones, bile acids, and vitamin D.