Source of ATP in RBCs is -

Ans. is 'a' i.e., Glucose* RBCs don't have mitochondria* RBC membrane integrity is maintained by Na+K+ATPase. This pump pumps out 3 sodium ions and reciprocally pumps in 2 potassium ions. In other words, this pump helps in maintaining low sodium concentration within RBCs. Sodium accumulation is avoided, as sodium attracts water, cells swell and rupture. This pump needs ATP.* The required ATP is to be provided by anaerobic metabolism* The only pathway that provides ATP even in anaerobic conditions is glycolysis.* The only fuel which can be utilized in glycolysis is glucose.* Hence RBCs utilize glucose as their fuel through glycolysis.* This is principally why glycolytic enzyme defects present with hemolytic anemia.