Use curved arrows (like those in Figure 22.3) to write an equa...

Question

Use curved arrows (like those in Figure 22.3) to write an equation for the conversion of fructose to fructose 6-phosphate by ATP. At what step does fructose 6-phosphate enter glycolysis?

Accepted Answer

All right. Hello everyone. So this question is asking us to provide the equation that shows the conversion of 13 bis phospho glycate to three phospho glycate by AD P determine the step at which three false f glycate enters the glycolysis pathway. So because for this question, we're going to examine the glycolysis pathway as a whole. Let's go ahead and talk about the steps of glycolysis in a more general sense. Now, recalled glycolysis is the breakdown of glucose into a metabolic intermediate known as pyruvate. Now, in addition to pyruvate, we're also going to produce ATP and an A DH. However, for the sake of this overview, I want to just focus on the organics molecules involved in each step of the pathway. This is because I want to focus on the question at hand, which is when three phosphor glycate enters the pathway. So just for your information and just to clarify, we do have the formation of A TP and N A DH. But for this question, I'm not going to focus on that because I would rather focus on the organic intermediates and organic products. So let's start with glucose, which is of course, the starting material of glycolysis, right. So in the first step of glycolysis, we have the conversion of glucose into glucose six phosphate from a glucose six phosphate. We have an isomerization reaction to go from fructose six phosphate into fructose six phosphate. This leads us now into the third step, which is where fructose six phosphate is converted into fructose, 16 bisphosphate. Now fructose, 16 p phosphate is a six carbon molecule that is going to be broken down in the fourth step of the pathway into 23 carbon products. One of them is glyceraldehyde three phosphate or G A three P for short, as well as dihydroxy acetone phosphate or DH A for short at this point. The fifth step of the pathway is another isomerization reaction in which dihydroxyacetone phosphate is converted into another equivalent of glyceraldehyde three phosphate. From this point onwards, glyceraldehyde three phosphate is the important intermediate for the rest of the glycolysis pathway. And for the record, this produces two equivalents of G A three P that react further. So from here, we have G A three P being converted into 13 bis phospho glycate or 13 B PG. From here we convert 13 B pg into three phospho glycate or three PG. I had forgotten to label steps six and seven. So apologies for that. But from here, three phospho glycerated is the product of step seven in the glycolysis pathway. So three phospho glycate is converted into two phospho glycate in step number eight, which is an isomerization reaction. Two phospho glycate is then converted into phosphoenolpyruvate in step nine and step 10, which is the last one is the conversion of phosphoenolpyruvate into pyruvate. So because three phospho glycate is produced after step seven of the pathway, step seven of the pathway is where three phospho glycate enters because it's where it's being produced. So with that in mind, let's go ahead and draw out our reaction scheme. So once again, the reaction in question is the conversion of 13 bis phospho glycate into three phospho glycate. Now, in the process, we're also using one equivalent of AD P and converting that into a TP. So let's start with 13 BPG. Now 13 BPG is going to involve two phosphate groups attached to carbons, one and three of a three carbon chain. Now this three carbon chain that's glycate is a three carbon sugar obtained from the oxidation of glycerol. So in addition to our phosphate groups, we have a car bal on position number one and a hydroxy group connecting to carbon too. So from here, we have a phosphate group being removed from carbon number one to produce three phospho glyceride. So there's still going to be a phosphate group on carbon number three. But now carbon number one is a carboxylate. So now the question is because a phosphate group is being removed, where exactly does it go. Well, this is where AD P is relevant for the reaction. Because the phosphate group from 13 BG is transferred from 13 BPG to adenosine diphosphate to produce adenosine triphosphate. And there you have it. So that actually completes our final answer. So just to add on here, what we had discussed towards the beginning of this video, we established earlier, the three phospho glycate enters the pathway at step seven because that is when it's being produced. And so with that being said, thank you so very much for watching and I hope you found this helpful.

Use curved arrows (like those in Figure 22.3) to write an equation for the conversion of fructose to fructose 6-phosphate by ATP. At what step does fructose 6-phosphate enter glycolysis?

Key Concepts

Curved Arrows in Organic Chemistry

Phosphorylation

Glycolysis Entry Point

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