What is Glycogen synthesis?

Glucose is stored as glycogen by activating glucose-6-phosphate to UDP-glucose (one UTP), which glycogen synthase adds to the non-reducing ends of the existing tree; a branching enzyme cuts and re-attaches short chains to make the $\alpha(1{\to}6)$ branches (Chapter 10). Synthase and phosphorylase are regulated in opposite directions by the same signals: the phosphorylation that switches phosphorylase on switches synthase off, so the tree is never built and dismantled at once.