RNA and its types

 RNA: 

                RNA  stands for ribonucleic acid. Unlike DNA, RNA is usually a single standard, However, some regions of the RNA show a double helix. RNA is synthesized from DNA during the process called transcription. It has nucleotides:

• Adenine 
• Cytosine
• Guanine
• And Uracil instead of Thymine

There are three types of RNA:

1: mRNA

2:  tRNA

3:  rRNA

 All these three types of RNA are synthesized in the nucleus from the DNA and then moved to the cytoplasm to perform their specific function

Messenger RNA:

        It makes up 3 to 4% of the total RNA. It takes the genetic message from the nucleus to the ribosomes in the cytoplasm to form the particular protein.  It is usually a single standard and its length depends upon the gene's size and the protein for which it is taking the message e.g: for the synthesis of the protein of the 1000 amino acid, the mRNA has a length of 3000 nucleotides Actually, 3 nucleotides in the mRNA encodes for the one amino acid and these three nucleotides along the strand of mRNA are called the codons of genetic codes.

Transfer RNA:

            It makes up 10 to 20% of the total RNA  These are the smallest RNA consisting of 75 to 90 nucleotides. It is usually a single standard but shows a duplex structure where some nucleotides bound to each other. It usually shows a flat cloverleaf shape in two-dimensional views. Its 5' end always terminates in the Guanine base while the 3' end is terminated with the base sequence CCA. Amino acid is attached to the tRNA at this end or the 3' end. The nucleotide sequence of the whole t/RNA is different. It has three loops.

   

• The middle loop consists of 7 bases the middle three of which form the anticodon of the mRNA.
• The D loop recognizes the activation of the enzyme.
• The Θ or the theta loop recognizes the specific place on the ribosome for binding during protein synthesis.
• There is specific tRNA for the specific amino acid.
• so a cell has at least 20 tRNA.
• Up to sixty tRNA have been identified. 
• Human cells contain 45 tRNA.
• As the name indicates, it transfers the amino acids to the site where proteins are synthesized.

Ribosomal RNA:

                 It is the largest type of RNA and usually duplex in structure and makes up 80% of the total RNA.

Ribosomes are made up of proteins and the rRNA where 40 to 50% of it is attached. On the surface of ribosomes, mRNA, and tRNA interact to translate information from genies into specific proteins. rRNA provides a platform for protein synthesis The sequence of rRNA nucleotides seems to be similar in bacteria, higher plants, and animals. So it undergoes fewer evolutionary changes.