Notice that on the deoxyribo sugar the second carbon does not have a hydroxyl group. However, the RNA molecules contain the ribose sugar and unlike the deoxyribose the ribosugar actually does contain the hydroxyl group found on the second carbon. So this is the ribosugar that is found on RNA molecules and that's exactly why our RNA stands for ribonucleic acid while DNA stands for deoxyribose nucleic acid. Now let's begin by let's move on to our nitrogenous base. So there are four different types of nitrogenous bases that are found in DNA. So we have guanine and anine which are the two types of purines and we also have the thymine as well as our cytosine.