Ribonucleic Acid (RNA)

RNA in a brief:

Ribonucleic Acid (RNA) is a nucleic acid polymer composed of ribonucleic acid polymers. Some virus’s genetic materials are only RNA. Part of ribonucleotide:

1. Phosphate
2. Ribonucleotide

• Ribose (Five- Carbon aldose monomer of carbohydrate)
• Nitrogenous Aromatic Alkaline Base

Purine:

• Adenine (A)
• Guanine (G)
• Inosine (I, Found in t-RNA)

Pyrimidine:

• Uracil (U)
• Cytosine (C)

Pic: RNA Types of RNA:

1. m-RNA (messenger RNA)
2. r-RNA (Ribosomal RNA)
3. t-RNA (Transfer RNA)

1. Messenger RNA (abbreviated mRNA) is a type of single-stranded RNA, responsible for protein synthesis. mRNA is made from a DNA template during the process of transcription. The role of mRNA is to carry information from the DNA in a cell’s nucleus to the cell’s cytoplasm (watery interior), where the protein-making machinery reads the mRNA sequence and translates each three-base codon into its corresponding amino acid in a growing protein chain.

2. r-RNA (Ribosomal RNA): according to britannica.com ribosomal RNA (rRNA), molecule in cells that forms part of the protein-synthesizing organelle known as a ribosome and that is exported to the cytoplasm to help translate the information in messenger RNA (mRNA) into protein. The three major types of RNA that occur in cells are rRNA, mRNA, and transfer RNA (tRNA).

   Molecules of rRNA are synthesized in a specialized region of the cell nucleus called the nucleolus, which appears as a dense area within the nucleus and contains the genes that encode rRNA. The encoded rRNAs differ in size, being distinguished as either large or small. Each ribosome contains at least one large rRNA and at least one small rRNA. In the nucleolus, the large and small rRNAs combine with ribosomal proteins to form the large and small subunits of the ribosome (e.g., 50S and 30S, respectively, in bacteria). (These subunits generally are named according to their rate of sedimentation, measured in Svedberg units [S], in a centrifugal field.) Ribosomal proteins are synthesized in the cytoplasm and transported to the nucleus for subassembly in the nucleolus. The subunits are then returned to the cytoplasm for final assembly.

3. t-RNA (Transfer RNA): According to britannica.com transfer RNA (tRNA), small molecule in cells that carries amino acids to organelles called ribosomes, where they are linked into proteins. In addition to tRNA there are two other major types of RNA: messenger RNA (mRNA) and ribosomal RNA (rRNA). By 1960 the involvement of tRNAs in the assembly of proteins was demonstrated by several scientists, including American biochemist Robert William Holley, who also developed techniques to separate different transfer RNAs from cells and determined the composition of the tRNA that incorporates the amino acid alanine into protein molecules.

   Ribosomal molecules of mRNA determine the order of tRNA molecules that are bound to nucleotide triplets (codons). The order of tRNA molecules ultimately determines the amino acid sequence of a protein because molecules of tRNA catalyze the formation of peptide bonds between the amino acids, linking them together to form proteins. The newly formed proteins detach themselves from the ribosome site and migrate to other parts of the cell for use.

Refferences:

1. Britanica.com
2. Hand note of nobleman