G Serine 14 of glycogen phosphorylase was replaced by glutamate in an experiment. The Vmax of the mutant enzyme was compared to wild type phosphorylase a and b. Vmax(µmoles of glucose 1‑phosphate released min−1 mg−1) Wild type phosphorylase a 100±5 Wild type phosphorylase b 25±0.4 Serine (S) to Glutamate (E) mutant 60±3 Explain the results obtained with the S to E mutant glycogen phosphorylase. The S to E mutant would mimic the phosphorylase in the T state. The reduced response is due to blockage of phosphorylase kinase’s catalytic site. Glutamate's negatively charged R group mimics a phosphorylated serine residue. The Vmax is reduced because the carboxyl group is smaller and less charged than a phosphate group. The S to E mutant would mimic the phosphorylase in the R state. The reduced response is due to blockage of phosphorylase kinase’s catalytic site. Glutamate's positively charged R group mimics the phosphoryl group on serine. There is a reduced response because the carboxyl group is smaller and less charged than the phosphate. What is the likely effect of a serine, S, to aspartic acid, D, mutation? more stimulation than the S to E mutant but less than the wild type a form more stimulation than both the S to E mutant and wild type a form less stimulation than both the S to E mutant and wild type b form some stimulation but less than the S to E mutant and wild type a form