We have all heard of DNA. But what exactly is RNA? RNA is similar to DNA in many ways at the structural level however; the differences that are present make RNA chemistry very different than that of DNA.
Everyday Chemistry - We know DNA. But what is RNA?
Almost everyone has heard of DNA and knows the role it plays in heredity. But another extremely important nucleic acid in the cell is RNA.
RNA or Ribonucleic acid is similar to DNA in many ways at the structural level. However there are certain differences that are present in RNA chemistry that make it very different than DNA.
What is RNA?
RNA serves many functions in a cell and is typically a linear polymer that consists of a sugar-phosphate backbone with nitrogenous bases projecting off the backbone. This structure is very similar to DNA. Both of these nucleic acids carry genetic information, which is based on the order of the bases that are present along the chain of the molecule. The presence of a single atomic change in the sugar molecule used in the synthesis of RNA makes its chemistry different from that of DNA.
Sugar-Phosphate: Backbone of RNA
The backbone structure of the RNA polymer encodes no genetic information but provides the linear, molecular pole off of which the different nitrogenous bases are hung. Just as in DNA, the sugar molecules are joined together through "phosphodiester bonds". This means that the sugar molecules actually have phosphate groups that are already attached to them. In fact, every sugar molecule containing "nucleotide" is used as a precursor in the synthesis of a nucleic acid. This molecule must contain a chain of three phosphates, which is separated by oxygen (O-P-O-P-O-P-O) and is attached to one specific carbon atom of the sugar, which is known chemically as the number 5 position.
Similarities Between RNA and DNA
RNA and DNA both encode specific genetic information. Both molecules use nitrogenous "bases" to convey this information. Adenine, guanine and cytosine (the letters A, G, and C) are used in both. The bases are attached to the sugar molecule through a bond at the number 1 carbon atom.
Structurally, both RNA polymers and DNA polymers are able to form a helical structure. DNA is well known for being present in cells as a double helix, where two strands of complementary DNA intertwine with each other. Most RNA inside a cell is synthesized as a single stranded molecule. Yet, it is well known for forming a large amount of double stranded regions when complementary sequences of bases within a single molecule form self-complementary double helices.
Thus, RNA is not very different from DNA and is just as important as our DNA.