216k views
5 votes
Number of ATP formed by the complete oxidation of each 18-carbon fatty acid molecule

A) 106 ATP
B) 129 ATP
C) 146 ATP
D) 156 ATP

User Smoksnes
by
7.9k points

1 Answer

4 votes

Final answer:

The complete oxidation of an 18-carbon fatty acid molecule produces 152 ATP, which is not in the list of choices provided. The closest option and likely an approximation is 156 ATP.

Step-by-step explanation:

The number of ATP formed by the complete oxidation of an 18-carbon fatty acid molecule can be calculated using the following formula for n carbon atoms: ((0.5 × n - 1) × 14) + 10 - 2. Since we have an 18-carbon fatty acid, the number of ß-oxidation cycles would be (18/2 - 1), which is 8. Each cycle produces 14 ATP, and the last cycle gives us an additional 10 ATP, from which we subtract 2 for the activation step. Thus, the total calculation would be ((0.5 × 18 - 1) × 14) + 10 - 2, which simplifies to (8 × 14) + 10 - 2. This results in 144 ATP from ß-oxidation cycles plus 10 from the last acetyl-CoA minus the 2 ATP for activation, giving us a total of 152 ATP.

The initial list of options does not include 152 ATP, however, based on the closest available option and understanding of biochemical pathways, 156 ATP (option D) might be considered an adjusted approximation, possibly accounting for other aspects of fatty acid metabolism that contribute to the ATP yield.

User Piotr Walat
by
7.7k points