Which statement identifies the primary glycolytic pathway used by red blood cells?

• A. Pentose Phosphate Pathway
• B. Embden-Meyerhof-Parnas Pathway (EMP)
• C. Methemoglobin Reductase Pathway
• D. Rapaport-Luebering Shunt

Answer: (B)

Red blood cells rely on glycolysis for their energy because they lack mitochondria. The Embden-Meyerhof-Parnas pathway is the glycolytic route that predominates in RBCs, converting glucose to lactate with a net gain of 2 ATP per glucose and regenerating NAD+. This ATP fuels essential work like maintaining membrane ion gradients and overall cell integrity. Other RBC pathways have important roles but are not the main energy-producing route: the pentose phosphate pathway provides NADPH to keep glutathione in the reduced form and protect against oxidative damage; the methemoglobin reductase pathway uses NADH to reduce methemoglobin; and the Rapaport-Luebering shunt diverts some glycolytic intermediates to 2,3-BPG to adjust oxygen release from hemoglobin. The Embden-Meyerhof-Parnas pathway is the primary glycolytic pathway for energy production in red blood cells.