<prompt> Fluoride is used inBlood glucose estimation samplesUrine glucose estimation samplesBoth 1 2None of the above  <response>: The high energy compound phosphoenol pyruvate is generated from 2-phosphoglycerate by the enzyme enolase. This enzyme requires Mg2 or Mn2 and is inhibited by fluoride. For blood glucose estimation in the laboratory, fluoride is added to the blood to prevent glycolysis by the cells, so that blood glucose is correctly estimated. 