Identify each of the following bases as a pyrimidine or a purine:
e. guanine

Question

Identify each of the following bases as a pyrimidine or a purine:

e. guanine

Accepted Answer

Welcome back, everyone which of the given compounds is a pyrimidine base. And we're given four compounds. The first one is uracil, the second one is end o the third, the third one is adenine and the fourth one is pine to. Um And for this specific problem, we want to recall the structure of a pyrimidine base. So basically, we have a six member ring with two nitrogen atoms, those nitrogen atoms are separated by one carbon. So we're drawing two nitrogens and a total of 1234 carbons. And then we simply want to add the three pi bonds, one of them followed by the second one. And then we have the third one. So that's a general pyramid base. In the context of this problem, we're looking for a structure that contains that six membered ring with two nitrogen atoms separated by one carbon. So when we consider ell, we notice that we have nitrogen followed by carbon, followed by another nitrogen and it is a six member ring. Notice that we only have one py bond because the other two py bonds simply disappear due to the presence of each carbona. But overall, it is the derivative of primidone. So we can state that uracil is the correct option. Now, indole is not a correct option because even though it has a six member ring, it doesn't contain any nitrogen atoms, the only nitro atom is within an additional five member ring, right? And we must have a six member ring plus two *** atoms. In this case, indole is not the correct option. Then we have adenine, right. So let's consider adenine. Now, adenine is a pura base and we have to recall that purine basis, they have an additional five member drain fused to the six member grain of pyrimidine. So let's draw that general structure. We basically have pine and then we have an additional five member ring with two nitrogens and they are bonded to the same carbon atom. Let's add the double bonds and also the hydrogen atoms to nitrogen. Notice that we have that six membered ring and the five membered ring and this is a purine base. So even though we notice pyrimidine in its structure, we also have to always check if there's an additional five member grain with two nitrogens, that would correspond to an overall purine base. And this is the case here. So adenine is a purine base and therefore, we cannot classify it as a primidone base even though it has that fragment of primidone, right? Just the presence of that five number R used to prim and now per the two on while we can immediately see that it only has a six membered ring with only one nitrogen. We need two of them, right? So it's not the correct option. Meaning the only correct option is A US O for this problem. Let's label it as our final answer. Thank you for watching.

Identify each of the following bases as a pyrimidine or a purine:
e. guanine

Verified video answer for a similar problem:

Key Concepts

Pyrimidines and Purines

Guanine

Base Pairing

Identify each of the following bases as a pyrimidine or a purine:e. guanine

Verified video answer for a similar problem:

Key Concepts

Pyrimidines and Purines

Guanine

Base Pairing

Identify each of the following bases as a pyrimidine or a purine:
e. guanine