Final answer:
During glycolysis, water is removed from 2-phosphoglycerate to form phosphoenolpyruvate via a dehydration reaction catalyzed by enolase.
Step-by-step explanation:
The transfer that occurs between 2-phosphoglycerate (2-PG) and phosphoenolpyruvate (PEP) during glycolysis is dehydration, where water (H₂O) is removed from 2-phosphoglycerate to form phosphoenolpyruvate. The reaction is catalyzed by the enzyme enolase. This process does not involve the transfer of a phosphate group, carbon dioxide, or hydrogen ions as the focus here is on the conversion between these two specific compounds in the metabolic pathway.