So the first thing I wanted to mention is just how this worksheet, which I call the clutch prep amino acid breakdown, is arranged. Well, all of the amino acid backbones have already been drawn for you, so all we're going to be doing here is filling in the side chains. That means anything that's attached to the R group that's attached over here. Also, I've included more information than you need for this video because this is information that we're going to use later. So, for example, these pKa values that you see here, don't worry about those yet. We're not going to talk about pKas yet. These little pizza slices, don't worry about those yet. You're going to understand what that means in due time. And also, there are going to be little boxes. Don't worry about them either like over here. We're not going to fill that in yet. These are for following videos where we talk more in-depth about amino acids. But the idea is that you can put all of your notes about amino acids onto the sheet. Every amino acid has a note section, so you can write in little tips and tricks, and the idea is that you keep the sheet for a long time. Maybe even after you take this class, maybe even after you graduate undergraduate. Like, you could even use this in med school, pharmacy school, whatever you have. Keep everything in one place, and then you'll always have a great way to memorize your amino acids if you ever need to know them later. So let's go ahead and get started with the first set of amino acids which are going to be the nonpolar side chains. Remember, these are the ones that are hydrophobic. They don't like to be around water. They're going to want to curl up and bulk inside of the protein. So let's start with the simplest amino acid possible. Hint, it's also the only achiral amino acid. Notice that all these other nitrogens or amine groups are on wedges, correct? But the first one is on a stick. Why? It's because glycine is the only amino acid that has a hydrogen as its side chain to add to the original hydrogen that was already there, that every amino acid has. So this is the only amino acid that is achiral. And that's why we draw it just plainer. Okay? In terms of how you can remember this, this is actually the only one I'm not going to give you a big memory tip for because it's just so easy. All I'm going to ask you to do is remember that glycine is where it all starts. It's the simplest one, and its three-letter abbreviation is Gly. Its one-letter symbol is G. It's just, just memorize that one and for the other ones, we'll be building on top of that information. Okay? Cool. So let's go on to the next one. The next one is alanine. So alanine is the simplest hydrocarbon. Okay? So hydrogen isn't technically a hydrocarbon because it doesn't have the carbon part. Alanine is going to be a methyl group, CH₃ for the side chain. The way I like to memorize that is that the symbol for alanine is A, the abbreviation is Ala, and I just think of it as being the easiest hydrocarbon, so it's A. It's kind of like A is the beginning of the alphabet and alanine is the beginning of the hydrocarbons where it's just a methyl group and nothing more. Okay. So we've got glycine, we've got alanine. Now, let's go on to valine. So for valine, now we have to start thinking about these hydrocarbon side chains and figuring out ways to memorize what they look like. So for valine, this side chain thankfully is also very easy because valine, the symbol for it is V, and the side chain looks like a V. All you have to do is draw a V coming off of that position and you have your valine. Now we have glycine, alanine, and valine. Let's move on to leucine. So now we want to draw leucine. How do you draw leucine? Well, this is another hydrocarbon, and it's actually also going to have a V. So by the way, you're going to notice at the end is that I want you to memorize these amino acids in this specific order because if you memorize them in this order, we can build a story behind them and then they can make more sense. So part of the story is that leucine looks a lot like valine. It's still got that V. We're just going to add an extra CH₂. Okay? What that means is I'm going to add an extra CH₂ here and then I'm going to draw that V. Now, the V it's kind of upside down now, but there you go. That's your leucine. So if you draw leucine right after valine, what you can think of is that, oh, leucine is just it's a little bit more complicated valine. It's going to be valine with that extra CH₂ right here. Okay? Awesome. Remember that leucine, like all these abbreviations, I'm not going to spend a lot of time on because they're easy. Leucine is L. All of them are straightforward. Great. So let's go into isoleucine. So isoleucine is also going to be a variant of valine, so it's also going to have that V except that now we're going to go back to the way things were for valine. We're going to draw that first and theniselectable mike"> we're just going to add an extra carbon. Okay? So technically, if you remember from like organic chemistry 1, isoleucine is an isomer of leucine, but the way you can really think about it is that it looks a lot like valine. It's got that initial V. You just put the extra methyl group all the way at the end. So see how if you memorize them in this order valine, leucine, and isoleucine, you can start to build a story of like okay, the V starts off only a V. Then it's add a CH₂ plus a V. Then it's add the V plus a CH₃. Got it? Okay. Cool. So now let's go on to proline. Now proline starts to get a little bit weird because proline is the only amino acid that connects back to itself. Okay? It's the only one you can tell. I kind of gave you a hint because I'm just going to scroll down to right here. I gave you a hint because notice that it's the only nitrogen that's missing a hydrogen. All the other nitrogens have c NH₂ and this one I only put NH. Why is that? Well, because proline, it turns out, has a 5-member ring inside of it that connects back to the nitrogen. So what we would do is we would draw a 5-member ring. 1, 2, 3, 4, 5. Connect back to the nitrogen, and you're done. That's proline. The way I like to think about proline is "proline pentagon." Okay? And if you think about "proline pentagon," that's always going to be a good hint for you, that now you need to draw a 5-member ring in that amino acid. Okay? Also, just keep in mind that these abbreviations and symbols are still straightforward. Proline is P. There's nothing really to talk about there. Great. So let's move on. So we're doing great guys. I think we're, how many are we down? 5 already? 5 out of 20? So what's next? Methionine. So methionine is also nonpolar. It's in the nonpolar category. However, it's going to be the first one that has a heteroatom. What that means is it's going to have an atom in the side chain that's not carbon. In fact, this is going to have a sulfur in it. Okay? So how can we remember that? Well, first of all, let's start with the structure. How would you draw the structure? Well, the way I like to think about it is the structure is in the name. Methionine starts with an M. In fact, the symbol is an M. So what I always do is I draw an M to begin with. Let's draw our M. 1, 2, 3, 4. Like that. So see how I just drew an M? Awesome. Now, we need to add a sulfur somewhere. Now, you're going to have to kind of remember this, but there aren't that many with sulfur. So it's not that hard to remember. So the sulfur actually goes in the second to last carbon. We would add a sulfur right here, and then we would just draw the rest of the M. So see how it still looks like an M, it just has that sulfur there. Now, how could you remember that the sulfur goes there and not somewhere else? Well, you could memorize it, but I also have another trick. Methionine says "meth" at the beginning, so you just make sure that there's one methyl group at the end. Right? So when you think about Methionine, it's an M that has a sulfur that allows for there to be one methyl group all the way at the end. And if you remember that, you've got your Methionine down. Awesome. So now we're going to get to some weirder ones. Tryptophan is