Starch serves to store energy for plants. Steroids Fatty Acids hydrophobic organic molecule chains of 4 to 24 carbon atoms with a carboxyl group at one end and a methyl group at the other. Triglycerides a neutral fat made up of three fatty acids bound to a molecule of glycerol. A peptide bond is formed between the amino group of one amino acid and the carboxyl group of the next. Secondary structure is a coiled or folded shape held together by hydrogen bonds.
Tertiary structure is formed by further bending and folding.
Quaternary structure occurs between two or more polypeptide chains. Examples of proteins Insulin and Hemoglobin Enzymes Enzymes are proteins that function as catalysts Enzymes are not altered by acting as catalysts Enzymes serve to lower the energy of activation in a chemical reaction, causing it to proceed. Enzymes are named for the substrate upon which they act, adding the suffix -ase active sites where substrate molecules attach.