<Li> aiding protein synthesis </Li> <Li> regulating various processes . </Li> <P> Protein synthesis is aided by functional RNA molecules such as tRNA, which helps add the correct amino acid to a polypeptide chain during translation, rRNA, a major component of ribosomes (which guide protein synthesis), as well as mRNA which carry the instructions for creating the protein product . </P> <P> One type of functional RNA involved in regulation are microRNA (miRNA), which works by repressing translation . These miRNAs work by binding to a complementary target mRNA sequence to prevent translation from occurring . Short - interfering RNA (siRNA) also work by negative regulation of transcription . These siRNA molecules work in RNA - induced silencing complex (RISC) during RNA interference by binding to a target DNA sequence to prevent transcription of a specific mRNA . </P>

What determines the function of the gene product