Fosfoenolpüruvaat

Fosfoenolpüruvaat, often abbreviated as PEP, is a vital organic compound found in all living organisms. It is a key intermediate in both glycolysis, the metabolic pathway that breaks down glucose for energy, and gluconeogenesis, the synthesis of glucose. PEP is a high-energy phosphate compound, meaning it stores a significant amount of energy in its phosphate bond.

In glycolysis, PEP is formed from the dephosphorylation of 2-phosphoglycerate. The enzyme pyruvate kinase then catalyzes the transfer of the phosphate group from PEP to ADP, forming ATP, the primary energy currency of the cell. This reaction is highly exergonic and serves as a major regulatory point in glycolysis. In gluconeogenesis, the reverse reaction occurs, where pyruvate is carboxylated to oxaloacetate, then converted to PEP, requiring energy input.

The energy stored in PEP's phosphate bond is crucial for driving cellular processes. Its role in energy metabolism makes it indispensable for life. Furthermore, PEP is a precursor for the synthesis of various amino acids and other important biomolecules. Its structure, characterized by a phosphate group attached to an enol form of pyruvic acid, contributes to its high reactivity and energy content.