Which of the following statements is true of all transfer (t) RNAs?
a. The 3′ end is phosphorylatedb. They are duplex chains
c. No methylated bases are found
d. The 3′ end base sequence is CCA
The answer is d.
For transfer RNAs, the 5′ end is often guanosine and is always
phosphorylated, while the 3′ end is CCA. Although transfer (t) RNA molecules
have many features in common, the primary feature that sets them apart is their
specificity for different amino acids and the corresponding specific
differences of their anticodons. Each tRNA is an L-shaped single chain composed
of up to 93 ribonucleotides. Each contains up to 15 methylated bases, and about
half of the nucleotides are base-paired into double helices. Activated amino
acids attach to the terminal 3′-hydroxyl group of the adenosine
