DNA backbone is made up of deoxyribose monomer sugars as the basic unit that are covalently connected in chains. Each deoxyribose sugar is a five (5)-carbon ring. The 5’ carbon covalently bonds with a phosphate while the 3’ carbon bonds to the next deoxyribose carbon ring. The 1’ carbon is covalently bonded to a nitrogenous base (either Adenine, Thymine, Cytosine, or Guanine ).
In DNA, Cytosine pairs with Guanine, and Adenine pairs with Thymine. In RNA, the same principle applies only that RNA has no Adenine base but Uracil. Therefore, Thymine pairs with Uracil while, similar to in DNA, Cytosine pairs with Guanine.
Covalent bonds occur in virtually all the bonds except between nitrogenous base pairs of opposite strands of DNA.
The central Dogma stipulates that DNA --à RNA--àProtein. During transcription, information on DNA is copied to messenger- RNA. In eukaryotes messenger- RNA moves to the cytoplasm where it is then translated to protein by ribosomes. In prokaryotes, since there is no nucleus, the mRNA is translated even as transcription continues.