Transfer RNA - Online Tutor, Practice Problems & Exam Prep

tRNA

Hi. In this video, we're going to be talking about transfer RNA. So transfer RNA, which is shorthand is tRNA, and this is responsible for translating a codon, so those 3 nucleotides, into a single amino acid. So this is the adapter, so to speak, between the codon itself and the amino acid. So the structure of a tRNA on it is, it kind of looks like a cloverleaf, some people say it's an L shape. But essentially it has two main regions that you need to know about. The first is an anticodon, and this is actually a sequence, so it's an RNA sequence, because tRNA is made up of RNA, which makes sense. So it's an RNA sequence, and this RNA sequence is complimentary to the codon in which it translates. So if the codon is ACC, then the anticodon would be what? It would be UGG, because we're working with RNA, GG. So this would be on the tRNA if it attaches the amino acid to this codon. Then on the other side of the tRNA, it has an amino acid attachment site. This is where the amino acid attaches so that it can be transferred during the translation process. Now tRNA doesn't exist with just amino acids on it. tRNA is just an RNA. There has to be an enzyme that actually adds the amino acids onto it, and so that is called an aminoacyl tRNA synthetase. And this is the enzyme that attaches amino acids onto tRNA's. Now there are 20 different aminoacyl tRNA synthetases, one for every single amino acid. So there's not one enzyme that does all of them, there's 20 of them, one for each amino acid. And when we have a tRNA that has an amino acid attached onto it, we call that tRNA charged. So a charged tRNA has an amino acid on. So this is what tRNA looks like. This is let me back up. This is why people say it looks like a cloverleaf, and this is why people say it looks like an L. And you can say whatever you want to, but this is entirely RNA. So the anticodon region is here in gray, you see it here, and so this is the anticodon. And the amino acid binding site is here, in this like goldish yellow color. So that's where the amino acid binds on to. And so understanding tRNAs and how they work is super important to understanding translation. So, with that, let's now move on.

Which of the following structures is not a part of a transfer RNA?

• A. Anticodon
• B. Amino acid attachment site
• C. Codon
• D. Clover leaf structure

Which of the following enzymes is responsible for attaching amino acids onto the tRNA?

• A. tRNA attachases
• B. Aminoacyl-tRNA synthetases
• C. Aminoacyl-tRNA attachases
• D. tRNA lysases