Intro to Amino Acids - Video Tutorials & Practice Problems
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concept
Intro to Amino Acids Concept 1
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Video transcript
We're going to say that amino acids are molecules containing an amino group and a carboxyl functional group. In addition to this, they're gonna have what's called an R side chain. If we take a look at this image here, we're going to say that this image we've illuminated this carbon here in purple that represents our alpha carbon. Our alpha carbon is basically in the middle of everything that's going on. In terms of our amino acid here, this alpha carbon is connected to an amino group here and then it's also connected to a carboxyl group. So this carbolic acid group here in addition to this, this alpha carbon has this R group here. And in this case, also, we're gonna say that this alpha carbon has this hydrogen up above. Now, you're going to say that this is the generic way of writing an alpha amino acid. We're so focusing on the alpha carbon in the groups attached to it. Now, physiological Ph is 7.4 in this type of environment. The amino acid takes on another form in this form. We're gonna say that our amino group has gained in H plus. And remember when nitrogen makes four bonds, it's positively charged. So now we have NH three positive here within this environment. It's slightly basic, basic enough that our carbolic acid has lost its H plus group. So now it's a carboxylate anion. We still have our, our group here R is just a placeholder for a hydrogen of carbon. A larger, more complicated group necessary. We'll talk about that later on. In addition to this, the alpha carbon is still connected to the sage. We're gonna say that this form that the amino acid takes within physiological Ph H is called your zoo an ion, your Twitter and ion is the molecule be bearing two groups of opposite charges. So in this case, we're talking about the amino group which is positive and the carboxylate an ion which is negative. Now, here we're going to say that there are 20 alpha amino acids and these are your standard amino acids and they're, they make up the building blocks of proteins and living organisms. So this R group, when it comes to alpha amino acids, the standard forms, there's 20 different types of R groups giving us these 20 different types of amino acids. Now we're gonna say they possess different R groups attached to the alpha carbon, right? So when it comes to our amino acid, remember we have our alpha carbon in the middle attached to our carboxyl group, our amino group in our group and then we have that hydrogen. So as we delve deeper into understanding amino acids, we'll see how this becomes more complex.
2
example
Intro to Amino Acids Example 1
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2m
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Video transcript
Here, it says that we need to label all alpha amino acids. Let's start with a all right. So we know that our carboxyl group is this carbolic acid group right here. We're gonna say here that our amino group is the nitrogen containing group here. That would mean that in the middle between them is our alpha carpet. So this is our alpha carpet. It is connected to a hydrogen that we know. And then look, we have this other group here something we haven't seen up to this point. This has to be our, our group. So this would label this off amino acid. Let's go to the next one. We have our carbolic acid. We have our amino group. Remember the carbon that connects them together would have to be the alpha carbon. So here's our alpha carbon here would say in this case, this one's a little bit different, a little bit more complex than what we're used to seeing. We're gonna say as a result of this, that this one should have this amino group attached directly to the alpha carbon here, but it does not. So this would represent not a traditional alpha carbon. Because the amino group should be directly attached to my alpha carbon, right? So here we say that this one deviates from what we're used to seeing. If we go to C for C, we have our carbolic acid group here, we have our amino group here, amino group here. The carbon that connects them together is our alpha carbon. It is connected to an H which would mean that this part which we haven't seen so far has to be a unique R group. Remember there's 20 different types of unique R groups here, right? So this is what we can say in terms of this. All right. So we'd say that A and C represent traditional alpha amino acids. B we see that the alpha carbon in the middle is not connected to an amino group. So it doesn't relate to our standard 20 amino acids that we're going to be seeing. All right. So B deviates from what we would classify as amino acid.
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Problem
Problem
What makes every standard amino acid unique?
A
presence of amino functional group
B
number of R groups bonded to the α-carbon
C
types of proteins they form
D
type of R group bonded to the α-carbon
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