Question

why is trna called an adaptor

Answer 1

The tRNAs, which accept the same amino acid are known as isoaccepting tRNAs. In the human mitochondria, there are only 22 different tRNAs and in plant chloroplasts, about 30. tRNA is frequently called an adaptor molecule because it adapts the genetic code for the formation of the primary structure of protein.

Answer 2

Just like the adaptor (a device that resembles a mobile charger), tRNAcomplexly attaches itself to the ribosome-mRNA complex through factors (initiation and elongation; not growth factors ;) ). This helps in inserting the correct amino acid by it's unique anticodon to mRNA codon