But this middle portion, the gamma structure shown red, actually rotate. So remember, as we discussed previously, it's this gamma structure that actually rotates as a result of the rotation of the C ring. As we'll see the next lecture that causes a change in confirmation of the beta subunit. So this is what we see in this diagram. So to see what we mean, let's begin with this diagram, which is basically this diagram here. And notice I've omitted the ATP molecules in the alpha subunits because the alpha subunits don't participate in this catalysis reaction, only the beta units do.