Translation is the process by which the information present in mRNA is read into proteins. The role of tRNA in this process is to accompany the according amino acid to the A-site of the translating ribosome. An average cell contains 60-70 different tRNAs. A size of 74-95 nucleotides is typical of the most tRNA species, except for some mitochondrial tRNAs. In the picture on the left you can distinguish certain features of tRNA structure:
At the top of the L-shaped molecule you see the acceptor stem which is identical in all tRNAs. The amino acid becomes attached to the adenosine residue of the 5'...CCA 3' sequence. In this case, the tRNA transports the amino acid serine (anticodon: 5' IGA 3'). Four or five base-paired regions (stems) are seperated by single stranded loops. In perspective of translation, the anticodon loop below is the most important secondary structure because it recognizes the codon on the mRNA. The sizes of acceptor stem, anticodon loop and stem are highly conserved through all organisms.

 color legend: acceptor stem: cytosine (blue) adenosine(violet),

 anticodon: inosine (magenta) guanosine (violet) adenosine (dark blue)