Question

how does the rate of glycolysis in red blood cells affect oxygen binding to hemoglobin?

Answer 1

Human erythrocytes (red blood cells) have no mitochondria. Since the mitochondria are the cellular site for oxidative metabolism of fatty acids, erythrocytes cannot oxidise fatty acids to release energy. The erythrocytes also cannot fully oxidise glucose (to carbon dioxide and water) because this is also a mitochondrial process, so they have to rely upon anaerobic glycolysis. The end product of anaerobic glycolysis is pyruvate, and erythrocytes reduce this to lactate (to recycle the NADH that is produced during glycolysis) and then export this lactate into the blood for further metabolism by the liver.

2,3-BPG is present in human red blood cells. It binds with great affinity with  deoxygenated hemoglobin.That's the reason the curve for hemoglobin in red blood cells is different with respect to the pure hemoglobin curve.

2,3-BPG is an allosteric effector to hemoglobin.2,3-BPG is a naturally occurring molecule that is produced as an intermediate in the glycolysis process. Deoxyhemoglobin in the T-state is a very unstable molecule and this drives the equilibrium towards the R-state, which means that deoxyhemoglobin will not exist for long and the majority of the hemoglobin will be bound to oxygen (i.e have a high affinity for oxygen). However in the presence of 2,3-BPG, this molecule will bind to the center pocket found in hemoglobin, thereby stabilizing the T-state of hemoglobin and allowing it to exist without quickly converting into the relaxed state. That is, by binding to hemoglobin, 2,3-BPG decreases hemoglobins affinity for oxygen, thereby shifting the entire oxygen-binding curve to the right side. This is what allows the hemoglobin to act as an effective oxygen carrier in the body, unloading about 66% of oxygen to exercising tissue.

The major role of red cells in binding, trans-
porting, and releasing oxygen and carbon dioxide
is a passive activity that uses, not consumes, these
gases. The erythrocyte's limited metabolic
processes, which include the Embden-Meyerhof
pathway and the hexose monophosphate shunt,
provide energy to accomplish several of the cell's
functions.