How many net ATP can oxidation of a 18 carbon atom fatty acid yield? 38 ATP ATP 18 ATP 144 ATP 36 ATP
The oxidation of a fatty acid can yield a total of 129 ATP. However, it is important to note that the production of ATP can vary depending on the specific fatty acid, the organism, and other factors. Additionally, the total ATP yield from the complete oxidation of a fatty acid will also include ATP produced from the citric acid cycle and oxidative phosphorylation. Therefore, based on the options given, the closest answer would be 36 ATP.
The oxidation of a fatty acid generates ATP through a series of reactions in a process called beta-oxidation. Each round of beta-oxidation involves the removal of two carbon atoms from the fatty acid chain, producing one molecule of acetyl-CoA.
An 18-carbon fatty acid would go through nine rounds of beta-oxidation, resulting in the generation of nine molecules of acetyl-CoA.
Each molecule of acetyl-CoA can enter the citric acid cycle (also known as the Krebs cycle) to produce energy. During the citric acid cycle, each acetyl-CoA molecule generates 3 molecules of NADH, 1 molecule of FADH2, and 1 molecule of GTP (which can be converted to ATP).
In total, for each molecule of acetyl-CoA, 3 NADH molecules, 1 FADH2 molecule, and 1 GTP molecule are produced.
Now, let's calculate the total number of ATP molecules produced:
- Each NADH molecule can yield approximately 2.5 ATP.
- Each FADH2 molecule can yield approximately 1.5 ATP.
- Each GTP molecule can yield 1 ATP (after conversion).
Based on this, the total ATP yield from one molecule of acetyl-CoA would be approximately:
3 x 2.5 (NADH) + 1 x 1.5 (FADH2) + 1 x 1 (GTP) = 7.5 + 1.5 + 1 = 10 ATP.
Since there are nine molecules of acetyl-CoA produced from the oxidation of an 18-carbon fatty acid, the total ATP yield would be:
9 (acetyl-CoA) x 10 (ATP/acetyl-CoA) = 90 ATP.
Therefore, the correct answer is 90 ATP.