One gram of fat stores twice as much energy as a gram of polysaccharide. More compact fuel reservoir than carbohydrate. Animals store more energy with less weight than plants which use starch, a bulky form of energy storage. Are major constituents of cell membranes. Lipids which have four fused carbon rings with various functional groups attached .
Cholesterol is an important steroid.
Is the precursor to many other steroids including vertebrate sex hormones and bile acids. Polymers of amino acids that are arranged in a specific linear sequence and are linked by peptide bonds. A macromolecule that consists of one or more polypeptide chains folded and coiled into specific conformations. Structural support 2. Though they vary in structure and function, they are commonly made of only 20 amino acid monomers.