When there is an excess of glucose, the body will store the extra glucose by attaching it together to form glycogen. What type of reaction is this?"

Anabolic reaction

Explanation:

The type of reaction involving the storage of extra glucose in the body as glycogen would be an anabolic reaction.

An anabolic reaction is a form of metabolism that involves the building up of molecules in the body of organisms. It is as opposed to catabolic reactions in which molecules are broken down in the body of organisms.

Most anabolic reactions require the consumption of energy while most catabolic reactions lead to the release of energy. Energy-consuming reactions are said to be endergonic while energy-releasing reactions are said to be exergonic.