Explain how glucose molecules are used to form glycogen in the liver, and why glycogen is a more suitable storage molecule than glucose.

Glucose molecules are linked together by condensation reactions, forming α‑1,4‑glycosidic bonds to give a long, branched polysaccharide called glycogen. The branching occurs through α‑1,6‑glycosidic bonds at the branch points.

Because glycogen is a large, insoluble molecule, it does not lower the water potential of the liver cells. In contrast, free glucose is soluble and would reduce the water potential, drawing water into the cells by osmosis and potentially causing swelling or damage. Thus glycogen is a more suitable storage form of glucose in the liver.