Important examples include the amino acids and acetic acid. These contain high levels of polyunsaturated fatty acids. Oleic acid undergoes the reactions of carboxylic acids and alkenes. All fats are derivatives of fatty acids and glycerol. Hydrolyzed collagen contains 8 out of 9 essential amino acids. Arachidonic acid is not one of the essential fatty acids. This compound is one of the naturally occurring proteinogenic amino acids. Thiamine is required for metabolism including that of glucose, amino acids, and lipids. They can produce isovaleric acid from branched chain fatty acids (BCFA). Glycine is one of the proteinogenic amino acids. Formic acid shares most of the chemical properties of other carboxylic acids. Sardines are a source of omega-3 fatty acids. Steatorrhea can lead to deficiencies in essential fatty acids and fat-soluble vitamins. Lysine is one of the nine essential amino acids in humans. Vegetable oils are rich in various polyunsaturated fatty acids (PUFA).