1
concept
Amino Acid Groups
2m
Play a video:
Was this helpful?
Hey, guys, congratulations. You finally made it through all unit One topics, which was mostly a refresher and review from your previous courses. But now we're transitioning into a new unit on proteins, and this is a heavy unit in biochemistry where we're gonna be learning a lot of things that you may not have learning your previous courses. And so the plan is I'm first going to tell you the most important things you need to know about amino acids. Then we'll transition into protein structure and protein techniques, and then we'll finally finish off talking about enzymes and regulation. So to get this unit started, let's first talk about amino acid groups. So, as you guys already know, there are 20 different amino acids that air called standard amino acids collectively. But they're also referred to as Alfa amino acids from time to time. And so these 20 standard amino acids they differ by there are groups, and we know that the amino acids are the monomers, or the lego pieces that are used to build proteins, and so these amino acids can be grouped together based on the chemical characteristics that there are groups display at physiological ph specifically and recalled that physiological pH is a pH of about seven. And so what you may not have known is that the common backbone of every amino acid is what's known as a die polar ion at physiological pH. And all that means is that there are two different charge species or two different charged groups on the backbone of every amino acids. So let's take a look at our example, which shows typical structure of an amino acid and recall that there's a central carbon atom, which is also known as the Alfa Carbon. Branching off is a central hydrogen atom, and then on either side we have to functional groups we have in Amino group, which notice is one of the charge species notice. It has a positive charge at Physiological pH, and then we have a car boxful group on the other side of the Alfa Carbon, which is the second charge species, making it a die polar ion at physiological pH. But we'll talk more about these ions and charges and another topic later on in our course. Now again, what makes each amino acid different from one another is the our group that it has, and these amino acids can be grouped together based on the chemical characteristics of there are groups. So we'll talk more about those groupings and our next video. So I'll see you guys then.
2
concept
Amino Acid Groups
4m
Play a video:
Was this helpful?
So in our last lesson video, we talked about how amino acids can be grouped together based on the chemical properties and characteristics of There are groups, and it turns out that amino acid are groups can actually be grouped in many different ways, and some textbooks group the amino acids slightly differently. And your professor might even group the amino acids in a slightly different way, then the way that we group them here clutch. But that's totally okay, because there's actually multiple correct ways of grouping the amino acids. And there's not a single, universal, correct way to group the amino acids. And that's because the groupings of the amino acids are actually relative to the way that you're trying to group the amino acids, and we'll be able to talk about that down below. Now you might be wondering, What do I do with my professor uses? A different grouping system may be hearing that there are multiple grouping systems gave you a little bit of anxiety. Well, first of all, I want you guys to know that here a clutch prep. We've chosen the most popular grouping system, and so it's very, very likely that your professor uses the same exact one is us. Now, even if you're Professor does use a different system, it's likely that it's only gonna vary just by a little bit. And so using clutches system is still gonna be very helpful and very effective for you guys. And so I promise I'm gonna get you guys to the point where you know, amino acids inside and out. And then you guys can slightly tweak what you've learned based on what your professor wants. And so if you're a little bit anxious, hang on tight and trust me on this one. Alright? So that being said, I want you guys to know that there are really two major ways to group the amino acids and the first major way is a functional grouping. And so the functional grouping has to do with the biological function off the are groups or the specific behavior that they are. Groups display under a certain setting. And so, for example, we have basic and acidic the behavior of the are grouped either accept the hydrogen or donate a hydrogen atom or polar and non polar. The behavior of the co violent bonds between specific atoms now, the second major way of grouping the amino acids is a structural grouping. And so, of course, the structural grouping has less to do with the behavior and mawr to do with just the structures or the presence and arrangement of atoms in the are groups. And so examples are like aromatic or al emphatic our groups. And so, because we have these two major different ways of grouping the amino acids, it turns out that some amino acids can be categorized into multiple groups. Now the good thing is, is that here a clutch prep with the system that we've chosen each amino acid on Lee gets categorized in tow one group. So that's very helpful and good to know. And what you'll see is that down below in this chart, in our example, we have all 20 amino acids listed out, and all of there are groups are highlighted, and so I don't want you guys to focus on. These are groups structures just yet. We'll eventually get to memorizing those, but in another video later, in our course for now, what I want you guys to focus on are the major groupings that we have on the side here and so notice that we have four major groupings. We have non polar, aromatic polar and charged. And so these air the groupings that are gonna help us, uh, group not only group the amino acids but also help us memorize the individual structures for each amino acid our group. And we'll be able to see how that works again later in our course when we get there. But first, what I want to do is to grow associate these groupings that we have with the major groupings that we have above. And so we already said that non poll, non polar and polar, which are up here, polar and non polar. We said that these two are types of functional groupings. So to color code things, what we'll do is we'll circle these as functional groupings, so non polar and polar are both functional. Now it turns out that charge is also a type of functional grouping, and that's because it has nothing, not a lot to do with the structure of the our group, but more so to do with its behavior under certain conditions. Now, what that means is that our Onley group that we have here, That is a structural grouping is the aromatic grouping. And so this is the one that is our structural grouping for the ones that we're gonna be focused on. And what you'll see is that the amino acids that fall in here all have aromatic rings. And so again, we're gonna talk about each of these individuals are groups later on in our course. But before we actually talk about those are groups. What I want you guys to notice is that each of these amino acids has an abbreviation at the bottom. It has, ah, three letter abbreviation and a one letter abbreviation, and so you'll see that at the bottom of all of our amino acids. And so first, we're going to talk about these amino acid abbreviations before we get to the structures. So that concludes our lesson on amino acid groupings, and I'll see you guys in our practice videos
3
Problem
Which of the following is not an example of a structural grouping of amino acids?
A
Hydrophobic
B
Sulfur-containing
C
Aromatic
D
Aliphatic