RNA Full Form

What is the full form of RNA?

RNA stands for Ribonucleic Acid. It contains a 5-carbon sugar called Ribose. It is a polymer nucleic acid. It is destroyed by alkaline solutions. RNA and DNA are two types of nucleic acids.They are a polymeric molecule which is necessary for various biological roles in the coding, decoding, regulation and expression of genes. RNAs are involved in protein synthesis.

This Story also Contains

1. What is the full form of RNA?
2. Structure of RNA
3. Types of RNA
4. a. mRNA
5. b. tRNA
6. c. rRNA
7. Functions of RNAs

Structure of RNA

RNA has a single-stranded helical structure. It is mostly present in the cytoplasm and produced from DNA by a process called transcription. Cellular organisms use messenger RNA (mRNA) to convey genetic information that directs the synthesis of specific proteins. The four major nitrogenous bases that RNA contain Adenine , GUanine (Purine bases) Cytosine and Uracil (Pyrimidine bases). These are denoted by the letters A, C, G and U. RNA contains a Uracil nitrogenous base instead of thymine. In RNA Pyrimidines are not equal to Purines. Its molecule replicates itself.

Types of RNA

RNA’s are classified into various types, some of which are involved in Protein synthesis and they each differ from the others by their size and function as follows:

1. mRNA

2. tRNA

3. rRNA

a. mRNA

• mRNA is known as messenger RNA.

• The mRNA carries messages from DNA to ribosomes for protein synthesis in the cell.

• There are a total of 5%(approx) mRNAs present in the RNA cell.

• mRNA is synthesised in the nucleus as heterogeneous RNA (hnRNA), which is processed into functional mRNA.

• The mRNA carries the genetic information in the form of codons.

• About 97% of RNA doesn’t code for protein synthesis, these RNAs are called Non-coded RNAs(ncRNA), which are encoded by their genes.

b. tRNA

• tRNA is known as transfer RNA. tRNA is also known as sRNA, for soluble RNA.

• tRNA contains about 10-15% of its total size. Its structure appears like a cloverleaf.

• It contains around 76-95 nucleotides in length, the most essential component of translation.

• It is a type of RNA which helps to transfer specific amino acids from cytoplasm to ribosome for protein synthesis.

c. rRNA

• rRNA is known as RIBOSOMAL RNA and it was discovered by Kuntze.

• It is found in ribosomes and it is produced in the nucleolus.

• It is a type of RNA which is present in ribosomes and reads the message of mRNA. And it is the most stable form of RNA.

• rRNA contains 80-85% of its total size in the cytoplasm of a cell, it is bigger due to its structure and the presence of mRNA and tRNA.

• The ribosome is a spheroidal particle and is composed of a large subunit and a small subunit.

Functions of RNAs

The structure of RNA is functionally the same as DNA, but there are some differences as follows:

• mRNAs serve as templates for protein biosynthesis and transfer genetic information from DNA to protein-synthesising machinery.

• If the mRNA codes for only one peptide, the mRNA is monocistronic. If it codes two or more different polypeptides, the mRNA is polycistronic.

• In eukaryotes most of the mRNAs are monocistronic.

• In eukaryotic cells, 10-20% of the nucleotides of tRNA may be modified and known as unusual nucleotides. They are,

  • Dihydrouridine (D)

  • Ribothymidine (T)

  • Pseudouridine (ψ)

• tRNA carries amino acids in an activated form to the ribosome for protein synthesis.

• Necessary to maintain ribosomal structure and also participate in protein synthesis by binding mRNA to ribosomes.

• Ribosomal RNAs may also provide some of the catalytic activities and thus is an enzyme “ribozyme”.