in this video, we're gonna talk about how to draw peptide. So a lot of times your professors expect you guys to know how to draw peptide. And really, the structure of a peptide could be drawn simply from its primary protein structure. And really, there are three basic steps to draw any protein, and we'll talk about Step number one in this video and our next videos. We'll talk about steps. Two steps. Three. So for step number one, the very first step and drawing a peptide is just to draw the peptide backbone and also toe identify the Alfa carbons and recall that the Alfa Carbons is just the central carbon atom where the our group is attached. And so the backbone actually consists of repeated atoms for each residue that's present. And so those repeated atoms are actually just a nitrogen, a carbon and a carbon. And so for each residue, there's going to be a nitrogen, carbon, carbon. And so that means that if there are two residues, then there's gonna be two sets of N. C. C. S. If there are three residues, then that means there's gonna be three sets of N. C. C. s. And so it turns out that this middle c here is always going to be the Alfa Carbon. And this last see over here is going to be the Carbonnel group carbon. And remember, the Carbonnel Group is just a C double bond. Oh, and so also recall from our previous videos that Onley, the very first and the last residues and a chain actually have free or ionized able ionized able amino groups or car boxing groups, respectively, in the backbone. So what that means is that the very first amino acid residue has a free amino group, but it lacks a free car boxing group. But the very last amino acid residue has a free car box a group, but it lacks a free amino group. And then all the internal residues lack both free amino and free car box of groups in their backbone. And so let's take a look at our example. So we can, uh, see visualized the various first step in drawing a peptide, which again is to draw the backbone and identify Alfa carbons. And so what you'll see is that we're gonna be drawing ah peptide, which has three amino acid residues. So we're only gonna draw an amino acid with three residues. So right that here And so because we have three residues, what that means is that we're gonna have three sets of the N C c. So let's go ahead and let's start drawing in R N C c. So we're gonna have a nitrogen here and N C c. That's for one residue. Now, our next residue is gonna be N C c. Perfect. And then we have our third residue. So it's gonna be N c. See? All right, Perfect. So now we've got our three NCC sets in there for each of our three residues. And so we know that the very first amino group over here is gonna be free and ionized well, so we can go ahead and draw in our NH three plus because we know that it's gonna be, uh, ionized at physiological pH and then a two very end over here. What we could do is drawing our car boxful group, which is also gonna be free, and so we can draw it as a car. Boxley and I am with a negative charge. And so the next part to do now that we've drawn in the backbone is to identify the Alfa Carbon. So recall that the Alfa Carbons are gonna be the middle C. So here's our N c c. So it's gotta be the middle c here. So this is gonna be our Alfa Carbon. So now let's check for the next one N c c. It's gotta be the middle one. So it's it's this one here and then for our last one. N c c. It's this one here. So this is our Alfa Carbon. So now we've identified the Alfa Carbons and we've drawn in the backbone and the last step here, What we're gonna do is just realized that over here, what we have is the end terminal end, and over here, what we have is the C terminal end, and that's it. So we have finished that number one, and so I'll see you guys in our next video where we'll talk about the second step to drawing a peptide
