MicroBiology

RNA is one of the nucleic acid. RNA stands for Ribose nucleic acid. RNA consists of long chains of nucleotide units. The nucleotides consist of the nitrogenous base, phosphate and ribose sugar. DNA and RNA are almost the same only there are some structural differences between the both. The structure of the DNA is usually double stranded while on the other hand the structure of the RNA is single stranded.

The nucleotides of DNA contain deoxyribose while that of the RNA contains the ribose only. Both the DNA has thymine as a base while RNA has uracil as the base. The enzyme called the RNA polymerases transcribes from the DNA. Later it gets processed over by some other enzymes as well. RNA is also known as the “main center for the protein synthesis”.

Structure of RNA

Each nucleotide present in the RNA comprises of a ribose sugar with carbons (the carbons are number between 1’ to 5’). Adenine, Cytosine, Guanine, Uracil are attached to the base to the 1’ position. Cytosine and Uracil fall under pyrimidines while the adenine and guanine fall under the purines. At the 3’ position of the ribose and 5’ position a phosphate group is attached. Due to the negative charge carried by the phosphate group, the RNA also becomes charged molecule.

There is a possibility of hydrogen bond formation between the guanine and cytosine or between guanine and uracil by the bases. Many other interactions also take place, interactions which involve group of adenine base binding with each other.

RNA has a hydroxyl group present at the 2’ position of ribose sugar which is one of the most vital features for distinguishing RNA from DNA. A-form geometry is adopted by the helix rather than B form due to the presence of the functional group. Due to this the major deep and narrow groove and wide shallow groove is formed.

Though originally RNA is transcribed of only 4 bases some other sugars and bases also mature in the RNA. A C-N bond to a C-C bond is changed by the Pseudouridine. Also, at number of places ribothymidine is found. Other such type of the modified base is the hypoxanthine whose nucleoside is referred as inosine. Inosine is very important as it plays the main role in wooble hypothesis of genetic code.