Now, let's take a look at these two sugar. Let's compare them and let's contrast them. So each of these sugars contain six carbon atoms. So we have carbon atom number one. So one, prime carbon number two, two, prime carbon number three, three, prime carbon number four, prime and carbon number five, five, prime. And the only difference between these two sugars is the fact that on the ribosugar we have this hydroxyl group attached to carbon number two.