 Okay, this is my kind of exam question here. Circle and identify the functional groups in vitamin C. So this is the structure of vitamin C. So whenever you take in vitamin C, this is the stuff you're taking. Okay, so we can see some functional groups here. The more apparent ones are the OHs or the hydroxy groups. Okay, so let's... No, let's not go all the way over there. There. So those are all the OHs. Those aren't really circles. I guess they're boxes or whatever. So all the OHs are, you can either call them a hydroxy group or alcohol. Now hopefully you can see the double bond here. This is the alkene. And then if you look here, we've got this structure. And this is actually an ester, which has the general formula of the carbonyl bonded to an oxygen, which is bonded to an R group, which is on the other side bonded to another R group. So that's the general formula for an ester. The general formula for an alkene, of course, is that. And the general formula for an alcohol.