Now, when we talk about a base catalyst, we say a base catalyst increases the rate of reaction by removing a proton from a reactant. So here, we have an alpha carbon because it's the carbon next to a carbonyl carbon. It is weakly acidic. So if we utilize a base, it can come in and remove this hydrogen. Carbon holds on to the electrons.

So carbon here has a lone pair, so it's negatively charged. And what we can do here is we have this \( \text{R-X} \) on the bottom, this alkyl halide, and now we've brought it over here because now we can finally react with it. So, this is going to use its lone pair, hitting this R-group, kicking out the halogen. So, what we've done here is we've added a carbon to the alpha carbon. So, this is an alkylation reaction.

This is the slow step in this process in which we're going to do this attack on this R-group to kick out the halogen. So here we've seen how a base catalyst can help to basically increase the rate of a reaction by first removing a proton from the beginning reactant.