<prompt> Substrate level phosphorylation in Glycosis is seen in which step?Glyceraldehyde-3-phosphate dehydrogenasePyruvate kinasePhosphofructokinaseEnolase  <response>: Conversion of Phosphoenol Pyruvate to Pyruvate Phosphoenolpyruvate is conveed to Enol pyruvate, the reaction is catalyzed by the enzyme Pyruvate kinase. The high energy PO4 of phosphoenolpyruvate is directly transferred to ADP producing ATP Refer box. Note Reaction is irreversible.ATP is formed at the substrate level without electron transpo chain. This is another example of substrate-level phosphorylation in glycolytic pathway Enol pyruvate is conveed to keto pyruvate spontaneously. Inhibitors Fluoride inhibits the enzyme enolase. CLINICAL IMPOANCE Sodium fluoride is used along with K-oxalate for collection of blood for glucose estimation. If K-oxalate is used alone, then in vitro glycolysis will reduce the glucose value in the sample. Functions of FluorideInhibits in vitro glycolysis by inhibiting enzyme enolaseAlso acts as anticoagulant,Act. as an antiseptic. Energetics: In this stage, 2 molecules of ATP are produced, per molecule of glucose oxidised. 2 ATPRef: MN Chatterjea Textbook of Medical Biochemistry, 8th edition, page no: 331 