In this video, we'll talk about some tricks that we can remember in order to draw purine structures. Now, a purine, the base form, is this. We have two rings fused together, and we see that we have four nitrogens embedded within those rings. Now for adenine, remember the structure of adenine, just remember adenine, ad amine, and amine is an NH₂ group. Here we're just going to add an NH₂ group to this structure. So here we'd still have a double bond on this nitrogen, and we would add our amine to this carbon right here, our NH₂ group. And this will represent adenine.

Now, guanine, if you remember the structure of guanine, we're going to say go first. This red oxygen indicates that we have a carbonyl. And there goes our red oxygen. Now because we have that carbonyl carbon there, it cannot make a double bond. Otherwise, it'd be making five bonds. Right? So a double bond cannot go here. That means this nitrogen is only making two bonds. Ideally, it wants to make three. To get that third bond, it has to connect to a hydrogen. So guanine, we have the go part. And then the second part is amine. So again, we have amine involved. An amine is an NH₂ group. That NH₂ group would go right here. So this represents our structures of adenine and guanine. But again, it all originates from the base form of purine, which is our two fused rings with four nitrogen atoms embedded within them.