What is the source of energy during the energy investment phase of glycolysis?

The source of energy during the energy investment phase of Glycosis are two ATP molecules.

Explanation:

During the energy investment phase of glycolysis, the energy source comes from two ATP molecules which then results in the formation of the two molecules of glyceraldehyde phosphate.

The two molecules of glyceraldehyde phosphate are then used for the second process of glycosis in which energy is emanated and not invested.

Glycosis is the process that is characterized by the breakdown of enzymes into smaller molecules and constituent elements.