When glucose molecules link up what substances do they form

Glucose is what plants make to get there energy, also known as sugar. Hope this helps.

When two glucose molecules come together, the two hydroxyl groups line up alongside each other: one combines with a hydrogen atom from the other to form water, in turn forming an oxygen bridge across the two molecules, bonding them and creating a disaccharide- this bond is called a glycosidic bond.

Cotton with iron probably