Editing Citric acid cycle (section)

== Efficiency ==
The theoretical maximum yield of [[ATP synthase|ATP]] through oxidation of one molecule of glucose in glycolysis, citric acid cycle, and [[oxidative phosphorylation]] is 38 (assuming 3 [[molar equivalent]]s of ATP per equivalent NADH and 2 ATP per FADH<sub>2</sub>). In eukaryotes, two equivalents of NADH and two equivalents of ATP are generated in [[glycolysis]], which takes place in the [[cytoplasm]]. If transported using the [[glycerol phosphate shuttle]] rather than the [[malate–aspartate shuttle]], transport of two of these equivalents of NADH into the mitochondria effectively consumes two equivalents of ATP, thus reducing the net production of ATP to 36. Furthermore, inefficiencies in [[oxidative phosphorylation]] due to leakage of protons across the [[Mitochondrion|mitochondrial membrane]] and slippage of the [[ATP synthase]]/proton pump commonly reduces the ATP yield from NADH and [[Flavin adenine dinucleotide|FADH<sub>2</sub>]] to less than the theoretical maximum yield.<ref name="pmid7654171">{{cite journal|vauthors=Porter RK, Brand MD|title=Mitochondrial proton conductance and H+/O ratio are independent of electron transport rate in isolated hepatocytes|journal=The Biochemical Journal|volume=310|issue=2|pages=379–82|date=September 1995|pmid=7654171|pmc=1135905|doi=10.1042/bj3100379}}</ref> The observed yields are, therefore, closer to ~2.5 ATP per NADH and ~1.5 ATP per FADH<sub>2</sub>, further reducing the total net production of ATP to approximately 30.<ref name="isbn0-7167-4684-0">{{cite book |vauthors=Stryer L, Berg JM, Tymoczko JL|title=Biochemistry|publisher=W. H. Freeman|location=San Francisco|year=2002|isbn=978-0-7167-4684-3|chapter=Section 18.6: The Regulation of Cellular Respiration Is Governed Primarily by the Need for ATP|chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK22448/}}</ref> An assessment of the total ATP yield with newly revised proton-to-ATP ratios provides an estimate of 29.85 ATP per glucose molecule.<ref name="pmid14641005">{{cite journal|vauthors=Rich PR|s2cid=32361233|title=The molecular machinery of Keilin's respiratory chain |url=https://www.researchgate.net/publication/8988933|journal=Biochemical Society Transactions|volume=31|issue=Pt 6|pages=1095–105|date=December 2003|pmid=14641005|doi=10.1042/BST0311095}}</ref>