Summary
Complete aerobic oxidation yields about 30 to 32 ATP, compared with 2 from fermentation.
In depth
Theoretical maximum was 38 but updated estimates are about 30 to 32 because of transport costs and proton leaks. Roughly: glycolysis 2, Krebs 2, oxidative phosphorylation about 26 to 28.
Estimates vary with the shuttle used for NADH (glycerol phosphate or malate-aspartate). Proton leak lowers yield.
Example: the revised yield is about 30 to 32 ATP.
The theoretical yield of aerobic respiration is up to 38 ATP in older textbooks, but modern estimates are about 30 to 32. Glycolysis gives net 2 ATP and 2 NADH; the link reaction 2 NADH; the Krebs cycle 2 ATP, 6 NADH and 2 FADH2.
With about 2.5 ATP per NADH and 1.5 per FADH2, the total is 2 + 2 + (10 NADH x 2.5 = 25) + (2 FADH2 x 1.5 = 3) = about 32 ATP. The yield is lower when glycolytic NADH is shuttled into mitochondria (costing ATP in some tissues) and when protons leak. Fermentation gives only 2 ATP.
Example: the difference explains why anaerobic muscle tires fast.
Key idea: numbers are approximate, because the ratio of protons pumped to ATP made is not a whole number.
Frequently asked questions
What is ATP Yield from Glucose?
Complete aerobic oxidation yields about 30 to 32 ATP, compared with 2 from fermentation.
Which area of biology covers ATP Yield from Glucose, and how advanced is it?
ATP Yield from Glucose is one of the 53 topics in Metabolism & Bioenergetics. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include NAD and FAD, Aerobic and Anaerobic Respiration, Cellular Respiration.
Can you give an example of ATP Yield from Glucose?
P/O ratios are about 2.5 for NADH and 1.5 for FADH2.
What should I learn before ATP Yield from Glucose?
Work through the Beginner topics in Metabolism & Bioenergetics first, such as Metabolism, Anabolism and Catabolism, ATP, then return to ATP Yield from Glucose. Intermediate topics assume the Beginner vocabulary.
What topics are related to ATP Yield from Glucose?
The closest topics to ATP Yield from Glucose are NAD and FAD, Aerobic and Anaerobic Respiration, Cellular Respiration, Oxidative Phosphorylation. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand ATP Yield from Glucose?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for ATP Yield from Glucose. To practise the whole of Metabolism & Bioenergetics, use the Metabolism & Bioenergetics quiz.
How is ATP Yield from Glucose different from NAD and FAD?
ATP Yield from Glucose: Complete aerobic oxidation yields about 30 to 32 ATP, compared with 2 from fermentation. NAD and FAD: Electron carrier coenzymes that shuttle electrons from catabolic reactions to the electron transport chain. Read both side by side and note what each one explains.
How should I study ATP Yield from Glucose step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with NAD and FAD and explain the difference aloud. Finally, take the Metabolism & Bioenergetics quiz and come back to this page for any question you miss.