Answer:

Explanation:
The metabolic pathway by which energy can be obtained from a fatty acid is called <u>"beta-oxidation"</u>. In this route, acetyl-Coa is produced by removing <u>2 carbons</u> from the fatty acid for each acetyl-Coa produced. In other words, for each round, 1 acetyl Coa is produced and for each round 2 carbons are removed from the initial fatty acid. Therefore, the first step is to calculate the <u>number of rounds</u> that will take place for an <u>18-carbon fatty</u> acid using the following equation:

Where "n" is the <u>number of carbons</u>, in this case "18", so:

We also have to calculate the amount of Acetyl-Coa produced:

Now, we have to keep in mind that in each round in the beta-oxidation we will have the <u>production of 1
and 1
</u>. So, if we have 8 rounds we will have 8
and 8
.
Finally, for the total calculation of ATP. We have to remember the <u>yield for each compound</u>:
-)
-) 
-) 
Now we can do the total calculation:

We have to <u>subtract</u> "2 ATP" molecules that correspond to the <u>activation</u> of the fatty acid, so:

In total, we will have 128 ATP.
I hope it helps!