Explain how we theoretically get 32 atp molecules per glucose oxidized in the liver, but only 30 atp molecules per glucose oxidized in the brain.

During the oxidation of glucose in the liver the malate aspartate shuttle system is used, therefore, two additional ATPs get generated at the step constituting glyceraldehyde-3-phosphate dehydrogenase.  

On the other hand, in the brain, a cell uses the glycerol phosphate shuttle system, which generates two less number of ATPs. However, the remaining of the energetics for the number of ATP in both cases are similar.  

Thus, the difference is based upon the kind of shuttle system used that leads to the production of 32 ATPs in liver cells and 30 ATPs in the brain cells.  

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