An RNA strand has an anticodon. Is it tRNA or mRNA?
Roles of 3 types of RNA – 1. mRNA mRNA (messenger RNA) – Function: carries information from genes to cytoplasm to be translated Many types of mRNA (many different genes) mRNA is fairly large (103-104 nucleotides depending on size of protein mRNA is short lived – turned over rapidly 2. tRNA (transfer RNA) Function: Allow amino acids to recognize the genetic code in mRNA Relatively small RNA – 80 nucleotides Are long lived – can be used over many times ~45 different types that are similar in structure Contain 2 critical sites amino acid attachment site – pair of nucleotides on one end anticodon site – 3 base sequence that is complementary to a codon tRNA attaches to specific amino acid and allows it to recognize the codon in mRNA through its anticodon tRNA – Critical step in translation Adding the right amino acid to the corresponding tRNA Accomplished by specific enzymes – aminoacyl-tRNA synthetases Amino acids must first be activated aa + ATP AMP-aa + PPi AMP-aa + tRNA aa-tRNA + AMP sy
