RNA
RNA stands for ribonucleic acid. RNA is made up of ribose, a five carbon sugar, and phosphate which forms the backbone. Attached to this backbone are 4 bases, in a similar way to DNA where cytosine (C) pairs with guanine (G) and thymine (T) pairs with adenine (A), in RNA C pairs with G, but A pairs with uracil (U) instead of T [1].
RNA involved in gene expression
- DNA is transcribed into mRNA, therefore the mRNA and the DNA are complementary
- This mRNA is then used as a template for translation into a functioning protein
- mRNA is also used to make copy DNA (cDNA)
2. tRNA – transfer RNA [3]
- consists of a sequence of three bases and an associated amino acid
- This molecule travels to the ribosome where a polypeptide is formed, the sequence of which was determined by the mRNA.
3. rRNA – ribosomal RNA [4]
- This is the RNA found in ribosomes
- It acts as a catalyst for protein synthesis
RNA can also exist in non coding forms. These non coding RNAs have many applications but many revolve around regulation of gene expression, such as Riboswitches in bacteria and miRNAs involved in RNAi (RNA interference) in animals.[5]
References
- ↑ Berg JM, Tymoczko JL and Stryer L, 2007, Biochemistry 6th edition, NY, W. H Freeman and Company, page 109
- ↑ Berg JM, Tymoczko JL and Stryer L, 2007, Biochemistry 6th edition, NY, W. H Freeman and Company, page 119
- ↑ Berg JM, Tymoczko JL and Stryer L, 2007, Biochemistry 6th edition, NY, W. H Freeman and Company, page 120
- ↑ Berg JM, Tymoczko JL and Stryer L, 2007, Biochemistry 6th edition, NY, W. H Freeman and Company, page 120
- ↑ Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P,2008, Molecular Biology of the Cell,5th Edition, New York, Garland Science, pg 493