Final answer:
The repeating unit that makes up glycogen is glucose. Glycogen is structured as a branched polysaccharide of α-D-glucose units, allowing for rapid glucose mobilization for energy.
Step-by-step explanation:
The substance that is the repeating unit making up glycogen is glucose. Glycogen is a large, branched polysaccharide that serves as a form of energy storage in animals, fungi, and bacteria. It is composed of α-D-glucose units joined by α-1,4-glycosidic linkages with branches formed through α-1,6-glycosidic linkages every 8-12 glucose units. Glycogen structure permits rapid mobilization of glucose when it is needed for energy, as it can be quickly broken down by enzymes such as phosphorylase into glucose-1-phosphate and subsequently into glucose.
Glycogen is a polysaccharide and is the storage form of glucose in animals. It is similar in structure to amylopectin, but it is more highly branched. Glycogen is made up of repeating units of glucose molecules joined together by alpha-1,4-glycosidic linkages, with branching occurring via alpha-1,6-glycosidic linkages. The branches are shorter and more frequent in glycogen compared to amylopectin.