By which of the following anticoagulants used in estimating blood glucose, glycolysis is prevented-

Ans. is 'c' i.e., Sodium Fluoride Fluoride inhibits Enolase, an important enzyme involved in Glycolysis This enzyme catalyzes the following step in glycolysis. Enolase 2 phosphoglycerate > Phosphoenol pyruvate.Inhibition of Enolase causes subsequent inhibition of Glycolysis.This property of Fluoride is utilized when blood is collected in tubes to estimate blood glucose.Fluoride inhibits glycolysis by inhibiting enolase, this will help in correct determination of the glucose level as glycolysis will not be able to affect the level of glucose.