This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of carbohydrate, Subject name: Biochemistry
End product of glycolysis in RBC is 
Select and explain. 
A. Pyruvate, B. Lactic acid, C. Acetyl CoA, D. Oxaloacetate
B: Lactic acid
Answer: B: Lactic acid 
Explanation: Under anaerobic conditions, the NADH cannot be reoxidized through the respiratory chain, and pyruvate is reduced to lactate catalyzed by lactate dehydrogenase. This permits the oxidization of NADH, permitting another molecule of glucose to undergo glycolysis. Under aerobic conditions, pyruvate is transpoed into mitochondria and undergoes oxidative decarboxylation to acetyl-CoA then oxidation to CO2 in the citric acid cycle. Glycolysis in erythrocytes always terminates in lactate, because the subsequent reactions of pyruvate oxidation are mitochondrial, and erythrocytes lack mitochondria. Reference: Harper; 30th edition; Page no: 171