Ans. a (Enolase) (Ref. Harper's Illustrated 26th ed., 137; 27th/Ch. 18)ENOLASE# The step of glycolysis catalyzed by enolase involves dehydration, forming phosphoenolpyruvate.# Enolase is inhibited by fluoride.- To prevent glycolysis in the estimation of glucose, blood is collected in tubes containing fluoride.# The enzyme is also dependent on the presence of either Mg2+ or Mn2+.# The phosphate of phosphoenolpyruvate is transferred to ADP by pyruvate kinase to generate, at this stage, two molecules of ATP per molecule of glucose oxidized.# The product of the enzyme-catalyzed reaction, enolpyruvate, undergoes spontaneous (nonenzymic) isomerization to pyruvate and so is not available to undergo the reverse reaction.# The pyruvate kinase reaction is thus also irreversible under physiologic conditions. EnzymeInhibitorPathway1.AconitaseFluoroacetateKrebs cycle2.L-KG dehydrogenaseArseniteKrebs cycle3.EnolaseFluorideGlycolysis4.Succinate dehydrogenaseMalonate oxaloacetateKrebs cycle5.Glyceradehyde-3 phosphateLactoacetate dehydrogenaseGlycolysis6.MOAIproniazid 7.Pyruvate dehydrogenaseArsenite 8.Carbonic anhydraseSulfanilamide