The D-loop in tRNA contains the modified nucleotide dihydrouridine. It comprises of 7 to 11 bases and is closed by a Watson Crick base pair. It is widely believed that it acts as a recognition site for aminoacyl-tRNA synthetase.
The T-arm or T-loop is a specialized region on the tRNA molecule that acts as a special recognition site for the ribosome to form a tRNA-ribosome complex during protein biosynthesis or translation.
The end of the tRNA molecule where the amino acid is supposed to bind is known as the acceptor arm. It 'accepts' the amino acid and binds to it, and has both a 3' end and a 5' end.
An anticodon is a trinucleotide sequence located at one end of a transfer RNA (tRNA) molecule, complementary to a corresponding codon in a messenger RNA (mRNA) sequence.
The variable region helps is stability of tRNA. The length of the variable arm is important in the recognition of the aminoacyl tRNA synthetase for the tRNA.
The CCA tail is a cytosine-cytosine-adenine sequence at the 3′ end of the tRNA molecule. This sequence is important for the recognition of tRNA by enzymes critical in translation.