 Hey everybody, Dr. O here. So now we've transcribed our DNA into RNA. Now it's time to translate it into proteins. Let's go ahead and dive in. So just like transcription, we're going to have the three steps, initiation, elongation, and termination. We're translating our RNA, which is in the nucleic acid language, into a protein, which is in the amino acid language. That's why it's called translation. So the three key players you see there at the top, when I say RNA, what I actually mean is mRNA. That's going to be the message that's going to be translated. The other key players are RNA or ribosomal RNA. The ribosome has that large and small subunit. The ribosomes in our cells are called ADS ribosomes. The ribosomes in bacteria are called 70S ribosomes. So the message is messenger RNA. The location where translation is going to occur is the ribosome or RNA. And then tRNA, transfer RNA, is going to be the actual translator. So we have the message, mRNA, the translator, tRNA, and the location where translation is going to occur, our RNA or the ribosome. There are different types of ribosomes, free ribosomes inside our cells. Make proteins that'll stay in those cells. Fixed ribosomes are part of the rough endoplasmic reticulum, and they're going to make proteins that leave the cell. I covered that in the video on the ribosomes. Okay. I think we are ready to get started. So I just wanted to show you the transfer RNAs, how they work. There should be 61 of these. Each one can read a three-letter sequence and then bring with it one of the amino acids. Obviously, there's not 61 amino acids. So I'll show you the code in just a minute. We only need to be able to bring 20 unique amino acids into a protein as we build it. So the steps. Initiation is going to begin at what's called the start codon, which is always AUG. So a codon is a triplet of bases or three bases on RNA that are converted or translated into the amino acid language. So the start codon is called AUG. We have the start codon is where initiation takes place, elongation. The messenger RNA is read three letters at a time and amino acids are brought. Notice that protein or polypeptide chain is being lengthened. Every time a new transfer RNA comes on, reads the next three letters, it leaves an amino acid behind which is bound together by peptide bond and that protein is going to continue to get longer and longer until termination. Termination is going to be when the ribosome runs into one of your three stop codons. So it goes start codon, elongation to the stop codon. Just like with transcription, it was promoter sequence of DNA determinator sequence. This is start codon to stop codon. Let me show you the genetic code. So you see the start codon down there AUG and this is the same genetic code that all living things use. So AUG it codes for methionine. So that's going to be your start codon. Then you have so 61 of these are called sense codons because they can be read. So CUU codes for leucine, CCU codes for proline, and then you're going to bump into one of your three stop codons at the end, also known as nonsense codons. Stop codons are fine, but I like to call them nonsense codons because it's not that this machinery can read it as a stop sign. It just can't read it at all. It's nonsense to it, which is why translation stops. So your three stop codons are UAA, UAG, and UGA. So you have your 61 sense codons, including the start codon, and your three nonsense codons. You'll notice though, so why we have 64 of these codons and only 20 amino acids. That's because your codons are triplets. If there were only two base pairs in a codon, we wouldn't have enough slots to have all 20 amino acids. So instead, you'll see that CCU, CCC, CCA, and CCG all code for proline. So some of these amino acids have four separate codons that will code for them. Some only have one, but there's some variation there. We'll talk when we get to mutations about how this is something called degeneracy. The fact that CCU and CCC both code for the same amino acid means that there could even be a mutation that could convert CCU to CCC, and it wouldn't matter because you'd still have the right amino acid in the right spot there. All right, so that's going to be translation. I hope this helps. Have a wonderful day. Be blessed.