One of the reactions catalyzed by using the cofactor FMN involves the enzyme glycolate oxidase. Glycolate oxidase is a peroxisomal enzyme. It catalyzes the oxidation of alpha-hydroxy acids. It is one of the key enzymes in photorespiration, where it oxidizes glycolate to glyoxylate. This reaction can be divided into to main steps. First, glycolate is oxidized to glyoxylate by FMN in a two-electron transfer. Then, the reduced FMN is reoxidized by oxygen and peroxide is formed. This reaction is shown below.