Question

Describe the roles of glycogen synthase and branching enzyme in glycogenesis, and predict the biochemical and potential clinical consequences in deficiencies of these enzymes

Answer 1

Glycogen synthase adds glucose to the glycogen primer, while branching enzyme creates branching points in glycogenesis. Deficiencies in these enzymes can lead to glycogen storage diseases and affect energy metabolism.

Step-by-step explanation:

Glycogen synthase is responsible for adding glucose to the glycogen primer by creating a-1→4 glycosidic linkages and forming a linear chain of glucose residues. Branching enzyme then removes glucose units from the linear chain and transfers them to another chain, creating a branching point with a-1→6 linkages. This process is repeated until glycogenesis is complete.

In deficiencies of glycogen synthase, the addition of glucose to the glycogen primer would be impaired, leading to reduced glycogen synthesis. In deficiencies of branching enzyme, the formation of branching points would be affected, resulting in decreased glycogen branching. These deficiencies can lead to glycogen storage diseases and impact energy metabolism.