Question

Describe the structure of a tRNA molecule.

Answer 1

What is the function of a tRNA molecule? What does the t and RNA stand for?

Answer 2

t stands for transfer. tRNAs carry specific amino acids, they interact with the RNA codons to bring said amino acid to the protein that is in the process of being built.

now, every tRNA has the structure of a clover leaf and therefore 3 "arms", which have their names by significant structures. one arm interacts with the mRNA, it is called the "anticodon arm". the second one is called TΨC-arm because of its characteristic Ribothymidine-Pseudouridine-Cytosine sequence.
The third arm is called D-arm because often you will find Dihydrourdine in it. Those are the three "clover leafs."

then, there is a fourth arm of variable length. this structure differs from and tRNA model to another and plays a major role in matching anticodon and amino acid. the amino acid sits on top of the fifth arm, atop a characteristic CCA sequence. I will attach a picture of a tRNA model, so that we are clear =)

Answer 3

http://upload.wikimedia.org/wikipedia/commons/5/59/TRNA-Phe_yeast_en.svg (source: wiki)

all the "arms" are called "loops", actually. messed that up through bad english :D