Biochemistry Glycogen phosphorylase catalyzes the first step in glycogen degradation. Glycogen phosphorylase requires: A Pyridoxine B Vit. B C Nickel D Cobalt 💡 Explanation Glycogen phosphorylase catalyzes the first step in glycogen degradation. Glycogen phosphorylase requires: ✓ Correct Answer: A. Pyridoxine