Number of ATP by oxidative phosphorylation from a 24 carbon fatty acid?
I have 96 because fatty acids go to CoA (2ATP) and the Krebs (22ATP). Glucose has 6C and so you add 2+22ATP and multiply by 4 to get 96. Is this right? If not, how do I figure this out?
To calculate the number of ATP produced by oxidative phosphorylation from a 24 carbon fatty acid, you need to consider both the process of beta-oxidation, which converts the fatty acid to acetyl-CoA, and the subsequent steps in the citric acid cycle (also known as the Krebs cycle).
First, let's review the process of beta-oxidation:
1. Each round of beta-oxidation removes two carbons from the fatty acid chain.
2. For every two carbon unit removed, one molecule of acetyl-CoA, one molecule of NADH, and one molecule of FADH2 are produced.
A 24 carbon fatty acid will undergo 12 rounds of beta-oxidation, resulting in 12 molecules of acetyl-CoA, 12 molecules of NADH, and 12 molecules of FADH2.
Now, let's move on to the citric acid cycle:
1. Each molecule of acetyl-CoA enters the citric acid cycle.
2. During one complete turn of the citric acid cycle, three molecules of NADH, one molecule of FADH2, and one molecule of GTP (which can be converted to ATP) are produced.
Since we have 12 molecules of acetyl-CoA from beta-oxidation, we will have 12 complete turns of the citric acid cycle, resulting in:
- 36 molecules of NADH
- 12 molecules of FADH2
- 12 molecules of GTP (which can be converted to ATP)
Now, let's calculate the total ATP production:
1. Each molecule of NADH can produce approximately 2.5 ATP when it enters the electron transport chain (ETC) and is oxidized.
Therefore, 36 NADH molecules can produce approximately 36 * 2.5 = 90 ATP.
2. Each molecule of FADH2 can produce approximately 1.5 ATP when it enters the ETC.
Therefore, 12 FADH2 molecules can produce approximately 12 * 1.5 = 18 ATP.
3. Each molecule of GTP can be converted to one molecule of ATP.
Therefore, 12 GTP molecules can produce 12 ATP.
Finally, add up all the ATP produced:
90 ATP (from NADH) + 18 ATP (from FADH2) + 12 ATP (from GTP) = 120 ATP.
So, the correct answer is 120 ATP, not 96.