As mentioned earlier, the factory where proteins are manufactured is an organelle called a ribosome
. A ribosome is a complicated combination of RNA and other proteins that carries out translation.
How is translation carried out? First, an amino acid is captured by a special kind of RNA molecule, a transfer RNA, or tRNA. A specific and different tRNA molecule exists in the cell for each of the 20 amino acids. The 20 tRNAs are roughly L-shaped molecules with two distinct and widely separated regions.
Click on the buttons below to see the regions indicated below in the structure of the phenylalanine tRNA at right.