NADPH via glycerophosphate shunt makes how many ATP?

NADPH via glycerophosphate shunt
makes how many ATP?
a) 1
b) 2
c) 3
d) 4
Correct Answer - B
Ans. is > b’ i.e., 2 [Ref : Harper 29"/e p. 129-130]
In glycerophosphate shuttle, the mitochondrial enzyme is linked to
respiratory chain (ETC) via a flavoprotein, So only 1.5 mol of ATP
are produced (According to older calculations, 2 ATP mol of ATP are
produced).
In malate shuttle, the mitochondrial enzyme is linked to ETC via
NAD, so 2.5 mol of ATP are produced (according to older
calculations 3 mol of ATP are produced).