Lipids are considered to be any of the following: waxes, phospholipids, sterols, fats, monoglycerides, diglycerides, triglycerides, certain vitamins, etc. Lipids are highly important for energy storage as well as providing our cells with membranes. Lipids are hydrophobic molecules. They are also unable to pack tightly together with other lipids do to their unusual shape. Triglycerides are the most widely utilized type of lipid for energy storage. These triglycerides are stored in adipose cells and are broken down by lipase enzymes. Triglycerides function in both animals and plants. The butter pictured above is plentiful in lipids.