What is the net gain of ATPs when Palmitic acid undergoes complete oxidation?
**Core Concept**
The complete oxidation of palmitic acid, a 16-carbon fatty acid, involves its breakdown through **beta-oxidation** and the **citric acid cycle**, ultimately producing **ATP** (adenosine triphosphate) as the primary energy currency of the cell. This process is crucial for energy production in the body. The calculation of net ATP gain involves considering the ATP yield from each step of the breakdown process.
**Why the Correct Answer is Right**
The breakdown of palmitic acid to acetyl-CoA units, which then enter the citric acid cycle, results in the production of **NADH** and **FADH2**. These electron carriers then donate electrons to the **electron transport chain**, generating ATP through the process of **oxidative phosphorylation**. For palmitic acid, the calculation involves determining the number of acetyl-CoA units produced (7 for palmitic acid, as it is a 16-carbon fatty acid and each acetyl-CoA is a 2-carbon unit), and then calculating the ATP yield from the complete oxidation of these units through the citric acid cycle and oxidative phosphorylation.
**Why Each Wrong Option is Incorrect**
**Option A:** This option underestimates the ATP yield from the complete oxidation of palmitic acid, not fully accounting for the ATP produced in the electron transport chain from NADH and FADH2.
**Option B:** This option overestimates, possibly counting intermediate steps incorrectly or misinterpreting the efficiency of oxidative phosphorylation.
**Option D:** Similarly, this option is incorrect, likely due to an error in calculating the number of acetyl-CoA units or the ATP yield per unit.
**Clinical Pearl / High-Yield Fact**
It's crucial to remember that the complete oxidation of fatty acids is a significant source of energy for the body, particularly during fasting or when glucose levels are low. The efficient production of ATP from fatty acids is vital for maintaining energy homeostasis.
**Correct Answer:** C. 106 ATPs