Primary Protein Structure - Video Tutorials & Practice Problems

Primary Protein Structure Concept 1

In this video, we're gonna take a look at the primary structure of a protein. Now we're going to say that the primary structure for protein is the sequence of amino acids attached through peptide bonds. Now, the structure is represented from the N terminus end to the C terminus end, if we take a look here at this sequence of amino acids, we see that on the left side, this is our N terminus N which is why we're pointing towards the amino group. And then on the right side, this is the C terminus end now pointing towards this carbonel, which was once part of a carboxyl group. You'll notice that we have these squiggly lines. Remember that just means that this amino acid is connected to other things. All we're doing is focusing on this segment of the sequence of amino acids. The same thing could be said here for this squiggly line, it's connected to something else. We don't know what it is. We're just focused on this portion. Now, we're saying that we're dividing each one of these amino acids or residues with these dotted red lines. So we can see in this image we have, let's see, we, if we're ignoring these ends, we're gonna say we see 1234 of these different peptide bonds, we see four peptide bonds. If we're ignoring the ones on the end, we're gonna see that we have five residues, we're showing that there's five residues by showing that we have our one group R, two, R, three, R four and R five. Now we're gonna say that the repeating N dash C dash C sequence forms the peptides backbone. So if you can see we have NCC NCCNCC, this is forming the backbone of our peptide. Now, we're gonna say here the backbone might either we're gonna see coil or bend the form our next level of protein structures. For. Now, we just need to remember that the primary structure of a protein is just a sequence of its amino acids connected through peptide bonds.

Primary Protein Structure Example 1

Which of the following statements about primary protein structure is incorrect peptide bonds that hold the amino acids together in the primary structure are covalent in nature. This is true because we see that it's the connecting of nonmetal atoms to one another. So nonmetal atoms or elements connected to each other is covalent in nature. So this is true. The peptide backbone is formed by repeating N dash C dash C sequence. We also saw this when discussing the primary structure of a protein. This is true. The standard representation of primary protein is from N terminus to C terminus. This is also true. So that leaves option D, the peptide backbone can have non amino acid parts. In addition to amino acid residues. Nowhere did we see when it came to our primary structure of our protein? Did we see anything other than amino acids being connected to one another through peptide bonds? We didn't see any of these non amino acid components. So this here is incorrect. So out of all the choices, the only one that's incorrect is option D

Do the following peptides have an identical primary structure?

• A. Yes
• B. No