Transfer RNA (tRNA) is a chain of 73-80 nucleotides that plays a role in protein synthesis. It binds to amino acids and transports them to the ribosome, the structure in the cell responsible for making proteins, so it can assemble them in meaningful patterns. Errors in transfer RNA can result in errors in the formation of proteins. Research on this subject includes studying how it works in normal conditions as well as understanding what happens when it goes wrong.
Each unit of transfer RNA has a distinctive cloverleaf structure. At one end, it has an anticodon arm that binds to messenger RNA in the ribosome. At the other, it has an arm that can form a covalent bond with a specific amino acid. The D and T arms on either side play a role in recognition and can be highly variable in structure and appearance. The transfer RNA itself is folded in a complex pattern, rather than being flat, as it might appear in simplified drawings and illustrations.
When a piece of transfer RNA connects to the messenger RNA in the ribosome, it has to find the right codon site to connect to while it grips its amino acid on the other end. Another piece of transfer RNA will hook up to the neighboring codon with its own amino acid. The two amino acids link, and the chain continues until the ribosome has built a complete protein. The length and structure of the protein can be highly variable, depending on the instructions encoded in the RNA.
This process allows cells to continually produce the proteins they need for various functions. The directions for making these proteins come from the organism's DNA, which encodes details that are translated by the RNA. One could think of the DNA as the air traffic controller that sends out messages and the transfer RNA as the ground crew that directs the amino acids to the right gates on the messenger DNA. The body is capable of repeating the production of proteins over and over again with a very low error rate.
Research on transfer RNA occurs in labs all over the world and was the subject of a Nobel Prize in the 1960s, recognizing the importance of researchers who successfully sequenced an example of tRNA. Their effort was all the more notable because they had to work with relatively primitive equipment, unlike the rapid and sophisticated technology available today.