<prompt> Glycogen phosphorylase coenzyme associated is?Thiamine pyrophosphateTetrahydrofolateFlavin mononuleotidePyridoxal phosphate  <response>: ANSWER: D Pyridoxal phosphateREF: Lehninger Principles of Biochemistry 4th edition page 562Pyridoxal phosphate is an essential cofactor in the glycogen phosphorylase reaction; itsphosphate group acts as a general acid catalyst, promoting attack by Pi on the glycosidic bond. This is an unusual role for this cofactor; its more typical role is as a cofactor in amino acid metabolismFlavin mononucleotide FMN, or riboflavin-5-phosphate, is a biomolecule produced from riboflavin vitamin B2 by the enzyme riboflavin kinase and functions as prosthetic group of various oxidoreductases including NADH dehydrogenase as well as cofactor in biological blue- light photo receptors 