When muscle cells have more glucose than they need for energy, they may store some of the excess as?

The answer is glycogen.

Explanation:

Glycogen is a polysaccharide of glucose that serves as a store of energy for muscle cells in animals and fungus.

Muscle glycogen turns into glucose in muscle cells and also in the liver is turned to glucose to assist the whole body including the central nervous system, which is the brain and the spinal cord.

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