Total Energy from Fatty Acids - Video Tutorials & Practice Problems
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concept
Total Energy from Fatty Acids Concept 1
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Hey, everyone. So in this video, we'll take a look at the total energy from fatty acids. Now, here we're going to say to calculate the total A TP yield from the complete oxidation of a fatty acid. We must consider two things. First, we need to consider the A TP from acetyl coa oxidation within the citric acid cycle or crept cycle. In addition to this, we need to think about A TP from N A DH and fa DH two are two high energy molecules that are in oxidative phosphor population. Now, if we take a look here, we're looking at this in relation to one cycle of beta oxidation, we're looking at crept cycle and oxidative phosphorylation. Our starting materials here, we're starting with our fatty acid. Remember we have to have fatty acid activation, which is a one time expense of two A TP. So here this would actually be minus two. We'd say that we would have the generation of one fa DH, two and one N A DH. Because that happens for every cycle, we make one of each and then we would have the creation of one acetyl coa since we're only going through one cycle of beta oxidation. Now, for Krebs cycle here we have that one cke and we would say that we would have the generation of one A TP one fa DH two and three N A DH s. Remember normally when we do glucose, we have the formation of two acetyl coa so these numbers would be double. But here, since we're only dealing with one acetyl coa, we only have half of each of these amounts. We would have our N molecule as oxo A. Now, here moving on towards oxidative phosphorylation, we have the dropping off of height of electrons by N A DH and fa DH two. So we wouldn't generate any of them. We would have the reduction of oxygen into water as our N molecule. But how much A TP would be involved? Well, we can see that we have a total of two N A DH S one from the beta oxidation and one from creb cycle. And we have four N ad agents. Remember that N A DH is 2.5 A TP. So times four, give me 10 and then we'd have two fa DH twos, each one is 1.5 A TP. So that's three A TP for a total of 13 AD P molecules. Now everything, everything, adding everything across the board, we have minus two plus one plus 13 that would give us a total of 12 A TP. And then we'd have one plus one is two and one plus three is four. Remember when we talk about crept cycle and oxidative phosphorylation, these are termed our common metabolic pathways, right? So this was the total that we would get for each one of these in terms of A TP FA DH two and N A DH. So keep this in mind when we take a look at the total energy involved with fatty acids.
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example
Total Energy from Fatty Acids Example 1
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4m
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Here in this example question, it says calculate the total A TP yield from the complete beta oxidation on Myristic acid. Here, this represents a 14 carbon atom fatty acid. So here, the way we start is we're gonna say step one, we have to calculate the number of cycles of beta oxidation. Now remember your number of cycles is number of carbons of the fatty acid divided by two minus one. So here we have a 14 carbon fatty acid divided by two minus one. So that'd be seven minus one. So we'd have six cycles. Next, we're gonna calculate the total number of N A DH and FA DH two produced during beta oxidation. This is equal to the number of cycles because we have six cycles. That means we're gonna have six N A DH S and six FA DH twos. Next, we have to calculate the total A TPN A DH and FA DH two produced during the citric acid cycle. Now, here this depends on the number of acetyl coa molecules from beta oxidation. Remember the number of acito K A is equal to the number of carbons of your fatty acid divided by two So it'd be 14 divided by two. So that means we'd have seven Aceto Coates. So here we have seven Aceto cos we would say that would be seven times one for seven A TP. We have seven times three which gives me 21 and a DH s and then we would say here seven times one which would give me seven fa DH twos. Remember this number of three and one for N A DH and FA DH two. We talked about that in the very beginning when it came to the amount of energy total energy evolved from a fatty acid oxidation. If you don't see that, go back to the previous video to see those values. Now, here we have to convert our total number of N A DH and FA DH two to A TP from oxidative phosphorylation. Now remember one A DH is equal to 2.5 A TP. One fa DH two is equal to 1.5 A TP. So based on our numbers here, what are we gonna do? We're gonna say here that we got 21 N A DH is here from the citric acid cycle. And then also remember we have another six N A DH S here based on the number of cycles when it comes to beta oxidation. So we'd have six plus 21 which gives me 27 and a DH S, we'd multiply that by the 2.5 A TP which would give me 67.5 A TP total based on an A DH. Now, here we have seven fa DH twos from the citric acid cycle and then another six that we got from beta oxidation based on the number of cycles. So that'd be six plus the seven. So give me 13 fa DH two. Remember each one is 1.5 A TP. So they give me 19.5 A TP. Then we're going to say add all the A TPS and remember there is a one time expense of two A TP involved. So here we'd add up the 67.5 A TP plus the 19.5 A TP minus the one time cost of two A TP. That will give me 92 A TPS total. So 92 would be the total amount of our A TP yield when we're talking about the complete beta oxidation of this 14 carbon atom fatty acid.
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Problem
Problem
Rank the following molecules based on amount of energy stored in them in increasing order (per mol).
I. Sucrose II. Arachidic III. Glucose IV. Behenic (22:0)
A
I, III, II, IV
B
III, I, II, IV
C
II, IV, III, I
D
IV, II, I, III
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Problem
Problem
Provide total moles of ATP produced by complete β-oxidation of 3.4 g of palmitic acid (256.43 g/mol).
A
1.4 ATP
B
31.2 ATP
C
106 ATP
D
1.43 ATP
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