Final answer:
A transfer RNA that has an amino acid attached to its 3' end is called an aminoacyl-tRNA.
Step-by-step explanation:
Transfer RNA (tRNA) that has an amino acid attached to its 3' end is called an aminoacyl-tRNA. During the process of tRNA "charging", the amino acid is activated and transferred to the tRNA, making it a charged or activated tRNA.
The 3' end of tRNA always has the sequence ACC, and the amino acid is attached to the terminal adenosine residue through an ester bond.