149k views
2 votes
Calculate the atp yield per carbon atom oxidized for tristearin.

User Elianne
by
6.9k points

1 Answer

3 votes

Step-by-step explanation:

Tristearin is a triglyceride composed of three stearic acid molecules attached to a glycerol molecule. Stearic acid has 18 carbon atoms. Since there are three stearic acid molecules in tristearin, there are a total of 54 carbon atoms (18 * 3).

When tristearin is metabolized, each stearic acid molecule undergoes beta-oxidation, generating 8 acetyl-CoA molecules. Each acetyl-CoA molecule enters the citric acid cycle, which generates 12 ATP molecules per acetyl-CoA (10 from oxidative phosphorylation and 2 from substrate-level phosphorylation).

Since there are 24 acetyl-CoA molecules produced from tristearin (8 * 3), the total ATP yield is 24 * 12 = 288 ATP molecules.

To calculate the ATP yield per carbon atom oxidized, divide the total ATP yield by the number of carbon atoms in tristearin:

288 ATP / 54 carbon atoms = 5.33 ATP per carbon atom oxidized.

User MusikPolice
by
8.4k points