glycojgne.pdf

Glycogenolysis - breaking down stored glycogen stores into glucose Firstly, glucogen is cleaved by the addition of orthophosphate (Pi), catalysed by Glycogen Phosphorylase Glycogen (n) +Pi ? Glucose 1-phosphate + Glycogen (n-1) Secondly, Glycogen 1-phosphorylase attacks the a-1,4 linakages until it...

Glycogenolysis - breaking down stored glycogen stores into glucose Firstly, glucogen is cleaved by the addition of orthophosphate (Pi), catalysed by Glycogen Phosphorylase Glycogen (n) +Pi ? Glucose 1-phosphate + Glycogen (n-1) Secondly, Glycogen 1-phosphorylase attacks the a-1,4 linakages until it reaches the a-1,6 linkages as it cannot prrocessess them. Debranching enzymes tranfers 3 glucosyl residues from the a-1,6 linkage to the a-1,4 linkage (main chain). The final molecule on the a-1,6 linkage is removed via hydrolysis using a-1,6 glucosidase Lastly, the glucose 1-phosphate is converted into glucose 6-phosphate by phosphoglucomutase. Glucose 6-phosphate can be directly metabolised. The phosphate from serine is transferred onto glucose 1-phosphate to make glucose 1,6-bisphosphate. The position 1 phosphate is then removed to give the final product of glucose 6-phosphate