 Are you ready to see how it works? Translation in action. First of all, what are you looking at? Go ahead, Pictionary. It's not Pictionary because I'm not drawing you a picture. Charades, but I'm not acting it out. What game is this where you have to guess what that is? I know you already know the answer. You're probably making everyone around you uncomfortable because you're yelling ribosome. Ribosome rigs, it's a ribosome and you are totally broken. It is a ribosome. You'll notice that it has the A site, the P site, and the E site. Now, oops, let's go. Who's coming? You know who's coming because check out the five prime cap. The mRNA is arriving to the scene ready to party with a ribosome. Who else is arriving just out of curiosity? What do you think that thing is up there? It's who? It's a tRNA molecule. The tRNA molecule carrying an amino acid. Now, if I were really amazing, I would go back and I would actually figure out what amino acid this was and make sure that it actually matched and I am just not that cool. Bummer. But look, this anti-codon is U-A-U. Is that the anti-codon? Who's just my example in the last thing? I'm just really curious. I want to know if it is. Oh, I was close. It was U-G-U. Okay, I'm almost that cool. Okay, U-A-U and it matches with the codon A-U-A. Let's see if it indeed works. Hey, and where does the tRNA bring the amino acid in the ribosome? To the A site, to the arrival site or the amino acid site. Okay, and then we form a bond. Now, this is the cool part. The ribosome is actually like an enzyme. It's a machine that once these molecules bind, the ribosome changes its shape slightly and it moves this whole thing along to the P site. So let's check that out. Here it goes to the P site. Now, we only have one amino acid. This is pretty much worthless so far at this point, but somebody else is arriving. And look at how the, whatever this is, matches. The anti-codon matches with the codon and brings in another amino acid. Now we've got two amino acids. Now this is where the ribosome is doing its magic. What happens is that the ribosome, again, it's just a chemical reaction. The ribosome manipulates things so that that first amino acid forms a bond, a peptide bond, pow, with that second amino acid in the arrival site. But now this is a chain. It's a chain of two amino acids. So technically, it's a peptide. The ribosome says, dude, get out of the arrival site and move to the peptide site where the peptides hang out. And now you've got your growing amino acid chain at the P site. Speculate. What's going to happen? What's going to happen at the A site? We're going to get a new arrival. What's going to happen at the E site? Dude, peace out, pound, you have nothing. You have nothing to offer us anymore. What's the matter with you tRNA molecule? Go back out and get yourself an amino acid and make something of your life. This tRNA molecule is going to have to leave. Look, it listened to me. It decided to go out and make something of its life. That's good. I'm glad it's listening. I hope my children someday listen as well. Here comes a new amino acid to connect with the anticodon, the anticodon and the codon match. The ribosome says, hey, we got somebody in the arrival site. Let's attach, pow, make a peptide bond, move everything on over, peace out, empty tRNA molecule. Go make something of your life, please. Come on in, new tRNA molecule. Now, this is something that I'm not sure that you realized. Some tRNAs do not have amino acids on them. If that tRNA is coded for, guess what? There's nothing to attach to. The ribosome says, I'd love to attach this chain to your amino acid, but there's no amino acid there. So what happens? It falls off. It's done. That means that that protein is ready to go and guess where it's going? It's going to go out and do something. It's probably going to be deposited into the endoplasmic reticulum, where it's going to get folded into a nice little shape and then exocyte toast out into the cytoplasm to go make something happen. Thank you for all of your work, tRNA molecules. You really did do something with your lives and now we literally have a protein. Are you happy? Do you understand that whole process? I wonder how long it keeps going. I think we're done. I know we're done. All right. How cool is that? Of course, you now have all the pieces, but none of it is ever that simple, ever. And so we're going to talk a little bit about how the whole process of protein synthesis is regulated and how we can end up with some diversity of stuff. And then we're going to look at critter diversity, like actually how critters can be really, really, really similar in their DNA and yet look really, really, really, really different. I'll be right back. Oops. I mean, I'll be right back. At least I caught it this time, right?