Phosphoenolpyruvate
Phosphoenolpyruvate is the last intermediate in the process Glycolysis, reacting to form Pyruvate. It is formed by the removal of water from the intermediate 2-phosphoglycerate in the presence of the enzyme enolase, creating a high energy enol phosphate linkage. ADP can be transfered to this high energy linkage in the presence of a pyruvate kinase enzyme, forming pyruvate and ATP.
Alberts, B et.al (2008) Molecular Biology of The Cell, 5th Edition, New York: Garland Science (p.121)