How to Memorize Amino Acids - Video Tutorials & Practice Problems
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Memorizing Amino Acids
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In this video, we're gonna consolidate all of the memory tools for memorizing all of the amino acids. So if you're looking for a good strategy to memorize all of the amino acids, I can recommend 2 things. And the first is to continue to watch clutch prep biochemistry videos. The more you watch, the more you'll get a hang of these memory tools. And the second is to get lots and lots of practice. And so, if you print and fill out this particular page and complete it from memory about 3 times or so, you'll start to get a better hang for the, memory tools, gavalinp, and what we have is GAVLYMP, and those are the non polar amino acids. So for the non polar amino acids, the mnemonic is GAVLYMP, where each of these letters represents the the one letter code for all of the nonpolar amino acids. And so the first one that we have is g, and g stands for glycine, so we can put the one letter code above. And glycine's r, r group is so easy that it just glides right on through. It's just one of the easiest ones, so it's literally just a hydrogen. Now the next that we have is alanine. And a, alanine's one letter code is a. And just like a is the first letter of the alphabet and it's easy to remember, alanine's R group is pretty easy to remember because it's just a methyl group. It's just a simple little methyl group. So it's just a CH3. And also, just like a is the first letter of the alphabet, it's the leader for all of the other letters in the alphabet. And what we'll see is that alanine really acts like a leader to all a lot of these other amino acid structures. And we can see that already when we go to our next amino acid valine. And so valine is, one letter code is v. And what we'll see is that really valine is just alanine with a v shape. And so if we draw an alanine, so c with an h, we know that the number of hydrogens are gonna change change and it turns out there's only gonna just be 1, but it's just alanine here with a v shape. And so there's alanine with a v shape and that's it. So it's just alanine with these 2 methyl groups coming off of it. Now the next one is leucine, and as you'll see leucine's one letter code is l. And l, leucine, is really just a loose extension of valine. So really, you can see how the structures here are building off of one another. So So valine built off of alanine, it's just a v shaped alanine. Leucine's building off of valine, so leucine is a loose extension of valine. So all you need to do is to make it a loose or extension is just to make the chain a little bit longer. So if we add in a c h 2, so we do c h 2, then a c h, and then we put in our valine, then we have our leucine. So you can see that leucine is literally just valine. So here's valine here, just a looser extension of it, so an extra CH 2. The next is isoleucine, and isoleucine's one letter code is I, so it's just an I. And what that means is that isoleucine is just an an isomer of leucine, so it has the same number of atoms and types of atoms. They're just arranged in a different way and the way to remember the arrangement is to just remember it's just a lopsided valine. So isoleucine isn't a lopsided valine. So all we need to do is draw valine. So there's valine and then all we need to do is make it lopsided. Perfect. So that is isoleucine. Now, the next that we have is Methionine, and methionine's one letter code is 'm', and really Methionine's r group is shaped like an m. So what we could do is just make that m shape. And then what we know is that at the very end there's going to be a methylthiol group. So methionine, when you write it out, methionine, notice that it has the meth part for the methyl group, and then it also has the thio part for the thiol group. So it has a methyl thiol and the only way to get the methyl thiol is to put the sulfur in right right here at this position. So that is methionine to R group and notice that it has an M shape, so it goes up, down, up and kind of right back down. So it's kind of like a sideways looking M. Now the next that we have is proline and proline's one letter code is p. And really what you'll see is that proline's, R group really looks like the loop of a p. And so, just like a p, when you draw a p, it has a backbone and then it has a loop. Well, the amino acid backbone kind of goes like this, side to side, and then the loop goes like this. So you can see that, proline's R group is the only one with the loop, so that's how it looks. And so really, it's also you can think of p for pentagon, so proline pentagon. And it's going to look like a pentagon because, again, it's going to, loop back like this. So it looks kind of like a pentagon. And really, all that we're seeing here is that they're all going to be c h two. So we're going to have a c h two here, we're going to have a c h two here, a ch 2 here, and then it connects back to that nitrogen. And again, notice that the number of hydrogens on the amino group is one less than all of the other amino acids. So it says n h two here instead of n h three, like all of the other amino acids, and that's because the R group loops back up and connects to the amino group. And so that's it for all of the non polar amino acids. Let's move on to the aromatic amino acids. And in the aromatic amino acids, we only have 3 amino acids, and those are Phenylalanine, Tyrosine, and tryptophan. And, our mnemonic is just fat young whippersnappers. And so, for phenylalanine, its one letter code is f. And really, phenylalanine alanine is trying to tell you what its r group is. It's literally alanine with a phenyl group. And so if we draw an alanine, so remember alanine up here is just a c h 3. So we draw in our alanine, so c h, we know the number of hydrogens are gonna change, it's gonna end up being just 2. But if we draw an alanine with a branching phenyl group, and remember a phenyl group is just a benzene ring, there we go. That's phenylalanine structure. The next that we have is tyrosine, and tyrosine's one letter code is y. And, basically, tyrosine is feeding off of phenylalanine. So we're seeing the same pattern up here where we see things kind of feed backwards, the structures are feeding backwards. And so, tyrosine is feeding off of phenylalanine. And really all we need to do to draw a tyrosine structure is redraw phenylalanine exactly. So we can draw our CH 2, we can draw in our, phenyl group. Okay. So there's phenylalanine, and then tyrosine is having a hydroxyl group baby, so it's basically just an Oh group coming off the bottom and that's Tyrosine's, r group. And then the last for the aromatic amino acids is w and w is for tryptophan. Let me put a w up here. And tryptophan's r group tries to trip you up, but we have these great memory tools. And so remember that tryptophan is just alanine with 2 joined rings. So let's go and, we know that the the 2 joined rings, there's a 5 membered ring and a 6 membered ring, and the 6 membered ring is the benzene, but the benzene goes at the bottom, so we're gonna draw it last or the benzene goes below, so we're gonna draw it last. And so we know it's, tryptophan is just alanine with 2 joined rings, so let's draw an alanine. So alanine again is CH 3, but we know the number of hydrogens are going to change and it's going to end up being just 2. And so then, we just need to draw our 5 membered ring. So let's draw our 5 membered ring. Perfect. There's our 5 membered ring. Now, the next step is to figure out where does the nitrogen go because we know that tryptophan has a nitrogen atom in it. And so to remember where the nitrogen goes, you just remember tryptophan trips on a tripod. And what that helps you remember, because a tripod has 3 legs, that helps you you remember that there's gonna be a 3 carbon start before you actually get to the nitrogen. And so we count out our carbons, here's 1, here's 2, here's 3, that means our nitrogen must go at this position here. And so, let's go back and erase these dots, put our nitrogen in here, and then, once we have our nitrogen in, it's figuring out where does the benzene go. And we have to remember that the benzene group or the nitrogen is not part of the benzene group and the benzene has to be below. So because the benzene has to be below, it can't be on either of these two sides. It can't be joined to the ring on either of those two sides. And it can't be on either of these two sides because, the nitrogen would be part of the benzene and the nitrogen cannot be part of the benzene. So then, it has to be that side there. So now we just draw in our benzene and there's our benzene. Perfect. And then the very last step is to draw in our double bond and our double bond does not touch the nitrogen or the benzene, so the only place it can go is here. And then, of course, you fill in the hydrogens at the very end and that is it for the structure structure of tryptophan. So now let's move on to our polar amino acids and there are 5 polar amino acids and the mnemonic to remember them is Santa's team crafts new quilts. So the polar amino acids, you think about the North Pole, of course Santa's there, you think of Santa's team serine. So here we have S, serine, and serine, just for serine. So here we have s, serine, and serine, just like alcohol is a serious threat, serine has an alcohol group and so really all serine is is, of course, our leader alanine is coming back into play. So notice that alanine is really, the leader for the aromatic groups here, starting the aromatic. And now we see alanine as the leader for the polar amino acids. So here's serine and, of course, it's gonna be building off of our leader alanine. So it's gonna be alanine, so it's gonna be a c h. We know the number of hydrogens are gonna change. It's gonna end up being 2. And then we say, okay, well, we even though Santa and his team know alcohol is a serious threat, so, serine and threonine are gonna have alcohols in them, they know that they can have it in moderation while they're making these, while they're crafting these new quilts. And so we can put alanine here with an alcohol group. That's all serine is, is alanine with an alcohol. And then threonine is really just building off of serines, groups. So threonine is t and what we're seeing is that it's building off of serines group. So, really, all we need to do to draw threonine is kind of redraw, serine here. And then all threonine has is an extra methyl group, it just has an extra methyl group. So if we put in a CH 3 over here, then there's only gonna be 1 hydrogen And so what you can see this is threonine's R group. And, another way to remember threonine, so its one letter code is T, another way to remember threonine is to remember that it has 3 parts on its only carbon. So its only carbon, which is here in the center, has 3 parts: a hydrogen, alcohol group, and a methyl group. Crafting hammer here, which spends a crafting hammer here, which spends a lot of quiet time in the Sistine Chapel, which is a church. And so anytime somebody makes a noise, cysteine is always like, shh. And so you can remember that cysteine is really just going to be alanine with the sh group. So it's gonna use our leader alanine again. So alanine, remember c h, we know that the number of hydrogens are gonna change, it's gonna end up being 2, and so it's just alanine with a group or an s h group, a sulfhydryl group, and that's it. That's cysteines R group. The next is asparagine and asparagine's one letter code is n. N. And so the n can help remind you guys of the amide group. And so, just like an n has these 2, parallel lines here, like that, that can help remind you of the double bond in the amide group. And so asparagine is just gonna be our leader alanine again, of course. So it's gonna be alanine, which of course is just c h. We know the number of hydrogens are gonna change, change, it's gonna end up being 2. And then it's going to be our amide group, so it's gonna be our C double bond O and our NH 2, and that's it. That is a spare gene structure. So you can see we have our amide group, it's alanine with an an amide group. And then our next and last polar amino acid is glutamine, and glutamine's, one letter code is q, as you can see here. And so, with glutamine, it's got that GLUT in it, and so it's going to be building off of asparagine's structure. And so, when you have the glute, you're gonna have the extra butt section or the extra c h two group. And so all you have to do to draw glutamine is to draw an extra c h two and you'll have glutamine structure. So let's go ahead and draw it in our CH 2. We know it's gonna have an extra CH 2 and then we just draw in our amide. And that is it. So you can see we've got our amide here and we've just got an extra CH 2. And so, glutamine structure is just that right there. And now we're finally into our, final and last, our 4th and last group, the charged amino acids. And the mnemonic is dragons eat, knights riding horses. Remember that the dragons eat, dragons eating things are it's really negative. There's really nothing positive about a dragon trying to eat you. And so dragon's eating is a negative, these are the negative amino acids. So d and e stand for, aspartic acid and glutamic acid. Those are the acidic ones. And remember, dragons, they shoot out fire and acid out of their mouth, so these are the acidic amino acids. Whereas knights riding horses, which stands for lysine, arginine, and histidine, these are the positively charged amino acids because, riding a horse is very noble, very positive. They're coming to save the day and fight the dragon, so it's very positive. And, knights do not spit acid out of their mouth, so, they are not acidic, they're going to be basic. So for our negatively charged acetic amino acids, the first that we have is d, and d is aspartic acid, so we can put in a d over here. And for aspartic acid, it's really gonna use our leader again all over. So notice that our leader alanine, which is up here, was used as a leader for phenylalanine for serine, and it's gonna be used as a leader again down here for our aspartic acid. So all aspartic acid is alanine, so we will draw in our c h. We know the number of hydrogens are gonna change, so it's just gonna be a 2. And with aspartic acid, it's gonna have a, carboxylic acid, so it'll have a c double bond o. And then, remember that the carboxylic acid is acidic and it can donate a hydrogen, and when it does that, it becomes aspartate. And so, let's draw aspartate here, which has a negative charge on it. And so what you can see is that we've got our carboxylate group, which is here, and it's just alanine with a carboxylate group and that's it. That's the structure of aspartic acid or aspartate. And the next that we have is glutamic acid. And again, glutamic acid, one letter code is just e. And notice that glutamic acid is really just building off the structure of aspartic acid because it's got that GLUT in it, and the GLUT just means that it has an extra c h two. It has a extra butt section. And so all we need to do to draw glutamic acid acid structure is to draw in an extra CH 2. So here's our CH 2, we know it's going to have an extra one, and then we draw in our carboxylate group. And so that is glutamate structure, so remember glutamic acid when it loses its hydrogen it becomes glutamate. So here's our glutamate structure and it has a carboxylate group and the extra c h two. So notice it has just one extra c h two in comparison to aspartic acid. And that's it for the negatively charged acetic amino acids. Then we move on to our positively charged basic amino acids, and we have the knights riding horses. So the first one is K and K is, it stands for the lysine. And just like K stands for a knight, lysine R group looks like a knight's sword and just like a k has 4 pointy points, 4 pointy, parts that you could try to stab somebody with, like just like with a knife or a sword you try to poke somebody with. There are 4 pointy points, so 1, 2, 3, 4. That helps remind us that there are a 4 carbon start to the chain. So we know there's going to be c h 2, c h 2, c h 2, and c h 2. And then at the very end of our four carbon chain, there's going to be an amino group, so it's just gonna be an n h three, and we know it's going to be positively coming back and completing and then coming back and completing arginine last. So let's do the same here. And histidine is, one letter code is just h. That's one letter code is just h. And so, remember that histidine just uses alanine all over again. Remember, alanine is just that c, c h, and we know the number of hydrogens are gonna change. So really all histidine is is it's alanine with a 5 membered ring. So, we know the hydrogens are gonna change, it's gonna up being 2, and then we know it's gonna be a 5 membered ring. So it's just gonna be 1, 2, 3, 4, 5. So there's our 5 member ring. And then just like the H in histidine has 2 parallel lines, we know that there's going to be 2 double bonds and 2 nitrogen atoms. And also, just like the H stands for a horse, histidine's R group really looks like a sideways horse. So all we need to do is draw in our 2 double bonds, draw our horse's legs. Legs. So here's the back legs, here's the front legs, and then we say, okay. Well, here's the neck, the nitrogen, right? And then, the nitrogen is going to have a hydrogen coming off. We know that the neck is the one that's positively charged, so this nitrogen here is gonna be positively be positively charged. If we want to, we can draw in a little tail for the back of our horse. And then once we have this, we've got our 2 double bonds, we've got 1 nitrogen, we know that there has to be a second nitrogen, so we have to remember where does that second nitrogen go. And, horse second nitrogen. So that means that the nitrogen can't go here or here because otherwise, the nitrogen, the horse would be stepping on the nitrogen. So then that means that the nitrogen must go here, and then all we need to do is just fill in our hydrogens, and that's it for the structure of histidine. And then, of course, last but not least is arginine, and arginine is, one letter code is just r, and so it's for the riding, and it's for riding in our mnemonic. And so, it actually has components of lysine and histidine, and so it's got components of the sword and the horse. And because it has components of the sword, we have to count up how many pointy ends are on the r that we could try to poke somebody with. And so our r has 3 pointy ends, 1, 2, 3. And so that reminds us that there's a 3 carbon start to our chain. So it's gonna be CH 2, CH 2, CH 2. Perfect. There's our 3 carbon start. And then also, just like our R has 3 pointy ends, that reminds us that there's a triangular nitrogen structure at the bottom. So triangular meaning that there's like 3 parts to it, 3 nitrogens. And so the way that this works is there's a nitrogen, there's a carbon, there's another nitrogen, and then there's a double bonded nitrogen over here. And then all you have to do at the end is just fill in the hydrogen. So this one has 1, this one has 2, this one also has 2, and it's really this nitrogen here that's gonna be positively charged. So it's the one that has a double bond that's positively charged, and this kind of looks like a person that's kind of riding a horse with these 2 double bonds here, kind of looking like the legs of someone riding the saddle of a horse sideways. And so, that's it. That's, all the mnemonics put together and all of our memory tools, and, hopefully, you guys will get more practice. Try to print this off a couple times and you guys will be good, and I'll see you guys in our next practice video.
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Problem
Problem
Fill-in the missing R-groups for the following peptide from memory: D-I-F-C-R-Q.
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Problem
Problem
Which of the 20 standard amino acids can be grouped into the following categories?
a. Contain cyclic/ring structures. b. Sulfur-containing.
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2m
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4
Problem
Problem
Fill-in the blanks & R-groups for each of the α-amino acids from memory.
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29m
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5
Problem
Problem
Match the amino acid to the type of R-group it has:
Leu ____ 1. Hydroxyl-containing
E ____ 2. Acidic
K ____ 3. Basic
Ser ____ 4. Sulfur-containing
C ____ 5. Nonpolar aromatic
W ____ 6. Nonpolar aliphatic
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Problem
Problem
Name the amino acids that contain each of the following in their R-groups:
a) Hydroxyl group: __________________ e) Sulfur atom: __________________
b) 2nd chiral carbon: __________________ f) Amino group: __________________
c) Amide group: __________________ g) Acidic group: __________________