Arachidic acid is a C₂₀ fatty acid found in peanut ...

Question

Arachidic acid is a C₂₀ fatty acid found in peanut and fish oils.

c. Calculate the total ATP yield from the complete β oxidation of arachidic acid by completing the following:

Diagram showing ATP yield calculations for fatty acid metabolism, including activation and products from acetyl CoA, NADH, and FADH2.

Accepted Answer

All right. Hello everyone. So this question is asking us to calculate the total A TP yield from the complete beta oxidation of benic acid, which is a 22 carbon unsaturated fatty acid. Use the table below. So for the table below, right, our task is to find how many molecules of a pseudo CO A N A DH and FA DH two are produced after the beta oxidation. In question. In addition, though our task is to create or rather calculate, excuse me, the amount of A TP produced from each process and then add them all together in this total row right here. So let's talk about some conversion factors, right? Let's do some math or rather before we go ahead and start doing that math, let's just talk a bit about beta oxidation itself, right? What does the reaction entail? Well, recall that after a series of four reactions, what's happening here is that the ch two of the beta carbon of a long chain fatty acid or fatty acyl group is converted into a keto group. So that's why it's called oxidation. And so once this beta keto group is formed in the first place a two carbon acetyl group is separated from the rest of the carbon chain which ultimately shortens the fatty aisle chain. So when asking yourself how many times a particular fatty acid can undergo beta oxidation? The question is how many of those carbons can be oxidized? And how many times can the carbon chain itself be shortened? So let's go ahead and calculate that. Let's calculate the number of beta oxidation cycles. So there's actually a formula for that. And so the number of beta oxidation cycles is equal to the number of carbons in the chain divided by two but subtracted by one. And the reason for this is because one of the carbons of the fatty acid is already a car bottle, right? It's the carboxylic acid group. So it's already oxidized. So now sub substituting in our numbers, we have 22 carbons in bohane acid divided by two would be 11, but then subtracted by one. And that gives us 10 beta oxidation cycles. And so this number is going to be a very important reference for our other calculations. So I'm just going to keep that here towards the top of the screen underneath our table. So from here, let's go ahead and calculate the total amount of NADH and FA H too. So as mentioned before, we have 10 cycles of beta oxidation to consider. So here for every one cycle of beta oxidation, we get one molecule of N DH and one molecule of FA DH two. So if there's 10 cycles, we have 10 molecules of N A DH and 10 molecules of FA DH too being produced. So now let's talk about how much Aceto coa is produced from this reaction. Earlier, we talked about how after every beta oxidation cycle, a two carbon Aceto group is removed from the carbon chain, right? And so that means that to calculate the number of acetyl coa produced from this particular starting material, all you have to do is divide the number of carbons by two, right? Because Aceto coa is made up of two carbons. So if we have 22 carbons in our starting material and we divide that by two, we have a total of 11 molecules of Aceto coa derived from the beta oxidation of botanic acid. So I'm adding that now to the table. So now the question is how much ATP is produced from each of these products. So now let me scroll down to do some more math. Now, for this question, it's important to recognize how much A TP is produced from each given intermediate. So recall that one molecule of an ad for example, typically yields 2.5 molecules of ATP, one molecule of FA H two generally yields about 1.5 molecules of ATP and last but not least one molecule of a pseudo coa remarkably produces 10 molecules of ATP. So now for each of these quantities of at P, we just have to go ahead and multiply it by the number of each product produced here. So for example, if we have 2.5 molecules of A TP for every one molecule of N A DH, we would multiply this by the number of N A DH molecules from the overall reaction which was 10, so 10 multiplied by 2.5 equals 25 A TP four N A DH specifically. So I'm going to be writing that here next to an ad in our table. And now we do the same thing for FA DH two, right? That's 1.5 AC P for every one FA DH two multiply that by 10 fa H two molecules and you get 15 at P. So I'll be adding that to the table as well. And then lastly, right, for every one acito away, we have 10 A TP multiply that by 11 molecules of A TP and you get a total, excuse me, 11 molecules of a PSEO coa and you get a total of 110 ATP molecules. So now we go ahead and add everything together, right? All we have to do is add the quantities that we just calculated, but then subtract by two ATPs consumed during the activation of this process. So 110 added to 25 added to 15, but subtracting two ultimately equals 148 molecules of ATP. And so that completes our table and therefore completes our final answer. And so with that being said, thank you so very much for watching. And I hope you found this helpful.

Arachidic acid is a C₂₀ fatty acid found in peanut and fish oils.
c. Calculate the total ATP yield from the complete β oxidation of arachidic acid by completing the following:

Key Concepts

Beta-Oxidation

ATP Yield Calculation

Fatty Acid Structure

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