Draw the condensed structural formulas for the products of the reaction of aspartate and α-ketoglutarate which is catalyzed by aspartate transaminase (AST).

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All right. Hello everyone. So this question is asking us to provide the structures of the compounds formed leucine and alpha ketoglutarate react with the presence of the catalyst, lucine transaminase or Lou T A for short. So here on the left side of the screen, I went ahead and pre drw the structure of leucine which is an amino acid. And on the right side, I have the structure of alpha ketoglutarate. Now, here it's important to mention that alpha ketoglutarate is an example of an alpha keto aid because if you consider the structure of this compound, what you'll notice is that we have a carbonyl directly adjacent to one of our carboxylic acid groups. So thats an alpha keto acid. So from here, let's talk a little bit about the trans emanation reaction and how to determine the structures of products given the starting materials. So the good news is that the name of the enzyme helps us out a lot because a transaminase like lucine transaminase is going to catalyze a reaction known as transamination. So what's happening here is that the amino group of the amino acid is transferred onto the other starting material in this case, the alpha keto acid. And so when it comes to drawing the structures of the products, you can think of it as a swap, right. So the compound that's the amino acid in the beginning before the reaction becomes the alpha keto acid after the reaction, and the alpha keto acid is converted into a new amino acid. So it's a switch. So now that we understand what products we expect to see, let's talk about how to draw the structures of the products from the structures of the starting materials. Now, here I went ahead and I labeled previously leucine and alpha ketoglutarate respectively. But now I'm going to go ahead and erase these labels because by the time our our modifications are complete, they will no longer be losing an alpha keto glory. So let's start with lucine here on the left side because leucine is our amino acid, the amino group that's on the alpha carbon is going to be transferred onto alpha keto glu. This means that leucine itself is converted into a new alpha keto aid. So taking the structure here of lucine, I'm going to start by erasing the amino group because that's no longer going to be present on this carbon chain. The alpha carbon, which is where the amino group was, was connected to in the beginning will now become a carbonel. So I'm going to take this hydrogen that's attached to the alpha carbon and I'm going to remove that as well to make the alpha carbon a car bal, if the hydrogen was still present, then carbon would have too many bonds attached to it. So now let's modify the structure of alpha ketoglutarate because alpha ketoglutarate is now going to receive the amino group that was removed from Lucy. And so that's going to happen on the alpha carbon adjacent to the carboxylic acid group. So what I'm going to do here is erased that car bono and instead connect the alpha carbon to the amino group except now the amino group should have a positive charge because it's gained an extra hydrogen. So it's an NH three, not NH two or NH three positive, I should say. So I've added now a single bond between that alpha carbon and the NH three positive, which means that I now added an extra hydrogen atom attaching to the alpha carbon to make sure that its for bond requirement is met. And so there you have it right. Lucine has now been converted into the alpha keto acid, whereas alpha ketoglutarate has now been converted into an amino acid. And so here are your two products. And so with that being said, thank you so very much for watching and I hope you found this helpful.

Draw the condensed structural formulas for the products of the reaction of aspartate and α-ketoglutarate which is catalyzed by aspartate transaminase (AST).

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Key Concepts

Transamination

Aspartate

α-Ketoglutarate