Consider the following tripeptide:
a. Circle the N-terminal amino acid, and give its name. Draw a square around the C-terminal amino acid, and give its name.

Question

Consider the following tripeptide:

a. Circle the N-terminal amino acid, and give its name. Draw a square around the C-terminal amino acid, and give its name.

Accepted Answer

All right. Hello everyone. So this question says for the following tripeptide, identify and label the N terminal amino acid and C terminal amino acid provide the name for each and here we have the structure of the tripeptide. Now recall first and foremost that when a peptide is drawn out by convention, it's going to be drawn from the N terminus to the C terminus going from left to right. So considering the structure that we're given right, we can see that on the very left side, we have the N terminus because we can see that free amino group that free prod amino group moving now to the right side, we can see that this is the C terminus because we have that free carboxylate group at the very end of the chain. So now let's go ahead and label starting here from the N terminus. We have the amino group of the N terminal amino acid as well as the alpha carbon right next to it and the carboxyl carbon. So that's what I'm adding into this box right here. Moving on now to the C terminus. I'm going to start at my free carboxylic group to the alpha carbon and lastly to the nitrogen of the amino group, that's now part of that peptide bond. So that marks now VC terminal amino acid. So just to clarify, on the left side, we have the N terminal and on the right side, we have the c terminal amino acid oops. So now let's talk about naming them. Now, recall that every amino acid has a unique side chain that can be used to identify that specific amino acid starting off with the n terminal amino acid and analyzing the side chain, we can see that the side chain is AC h2o H. So it's one additional carbon connecting to a hydroxy group. This if you recall is characteristic of Siri. So that's our end terminal amino acid. So moving on now to the c terminal amino acid and once again, looking at its side chain specifically, we also see a hydroxy group. But the difference now is that the side chain contains two carbons and the hydroxy group is connecting to the first carbon closest or rather attached directly to the alpha carbon, which is the center of the amino acid itself that therefore is characteristic of 3D, which would make thine the c terminal amino acid. And there you have it here is our final answer. So now we have the n terminal NC terminal amino acids identified. And so with that being said, thank you so very much for watching and I hope you found this helpful.

Consider the following tripeptide:

a. Circle the N-terminal amino acid, and give its name. Draw a square around the C-terminal amino acid, and give its name.

Verified video answer for a similar problem:

Key Concepts

N-terminal and C-terminal

Amino Acids

Peptide Structure