So the absence of the hydroxyl and second carbon of the sugar molecule found on DNA makes DNA more stable and more resistant to hydrolysis than the RNA molecules. Now let's move on to something called a backbone. So, previously, when we introduced nucleic acids we said that a certain part of the nucleic acid is known as the backbone. So before we discuss what the backbone is let's actually discuss how the different nucleotides are actually linked together in our polymer. So, remember, just like in proteins, we have these monomers known as amino acids, linked together by these special bonds known as peptide bonds. In nucleic acids, we have these monomers, our nucleotides, linked together by special bonds known as three to five phosphol diaster bonds or phosphol diaster linkages.