Question

Assignment II1-3: Prepare an essay ( 2pages) that discusses the various roles of RNA. How does the role of RNA differ from the standard role of RNA as expressed in Central Dogma, i.e., what other roles does RNA play?

Answer 1

The central dogma of life:

DNA ------> RNA -----> Protein

The major role that was originally perceived for RNA is to serve as an intermediate between DNA and protein i.e. it contains codons required for protein synthesis. However, RNA molecules perform several structural and catalytic functions in the cell

i. Ribosomal RNA is one of the structural components of ribosomes. Peptidyl transferase activity lies in the RNA component of the ribosome.

ii. tRNA serves as a carrier molecule to transport amino acids to the translating ribosome

iii. miRNA/siRNA mediate regulation of gene expression by binding and degrading the target sequences

iv. miRNA/siRNA mediate regulation of gene expression by binding and inhibiting the translation of target sequences

v. Some miRNAs and siRNAs are involved in viral/bacterial resistance

vi. Some small noncoding RNAs are involved in epigenetic regulation