<prompt> Which of the following is required for glycogen phosphorylase in glycogenolysis?Thiamine pyrophosphatePyridoxal phosphateFADCitrate  <response>: Ans: B Pyridoxal phosphate Ref: Harpers Illustrated Biochemistry, 28th edition.Explanation:Glycogen phosphorylaseThis enzyme catalyzes the rate-limiting step in glvcogenolysis by releasing glucose-i- phosphate from the terminal alpha-1, 4- glycosidic bond.Glycogen phosphorylase has a pyridoxal phosphate PLP. derived from Vitamin B6 at each catalytic site. 