okay so this lecture will cover translation so remember translation is the process of going from our RNA transcript over to our protein right so we already talked about what happens when we write down the copy of that Gene that was writing down the recipe from this big old recipe book but now let's talk about how we're going to actually make a functional protein from just some instruction so how do you actually bake the cake bake the pie from the recipe that's what translation is the process of synthesizing that specific poly peptide or making the product so if you saw this and I said I have a map that shows you exactly where an A in BIO 102 is at you just have to follow the instructions what would you need to interpret this I hope you said you would need some type of key right some type of key that lets you know what this symbol oops to let you know what this symbol means versus this symbol right you need something to kind of help you out so that's what we're going to be using we're going to be using a key um that's going to help us understand that long code of sequences that we've been making through our mRNA and help us to make a protein from it so the long code that we've been making is called a genetic code genetic code right right this is a u c c g c a g g right that is our genetic code very important this genetic code is read in a particular way it is read in groups and those groups are called codons so these are groups of three so every time we see a genetic code right I'm going to write one across the top a u g c c a g a g every time we see them we always want to read them in groups of three because that's how you read these codes they're called codons groups of three so every time we see these codes we want to automatically separate them into groups of three or or codons these codons are going to all specify a very particular amino acid so each of the letters are going each of the groups of three are codons so each group of three letter will represent some type of amino acid so if you see on this list here we have um amino acids such as um methylene veine alanine glycine um what you see here on the right is the three-letter code for what they're called and in the middle you're going to see the actual codon that makes it up some codons are going to tell you when to start making that polypeptide and some are going to tell tell you when to stop making the polypeptide so the start codons are going to be um pretty much Aug a great way to remember that is think about when school starts school typically starts in August right so that's a great way to remember Aug or the start codeon for this entire sequence Aug um there are multiple stop codons so you have um UAA you have u a and you have U GA so anytime you see that codeon that means we're stop we're stopping our our process of Translating that mRNA code and this is what we call a degenerate code which means that more than one codon can specify a specific amino acid so you can see that you have multiple codons are going to make um th right so it's going to be a lot of different ways to get the um amino acids that we have so let me show you how to this chart because you definitely will have questions in which you have to translate a particular sequence of DNA and we um sorry of RNA we'll go through that so the first thing you want to do on this chart now this is important is you want to let's say I'll just give you a random uh random sequence I'll give you a few so you can practice on your own just gave you three random ones so we'll start with the first one which is ug so the first thing you want to do is once you have identified the group of three right so when you get a code and we'll do one you want to start marking off groups of three that's step number one marks off mark off groups of three then you want to go through each group and identify what amino acid they make so u g we would first look on the left side this is telling us the first letter so these are the possible letters it could be we first find the first letter which in this case it is U so we're going to start right here so now our answer has to be somewhere on this row then you say what is the second letter second letter is G so we're on our first row we go over to second letter across the top G so now we know it's in this box and then we just finish the rest of the code it's u g so we find find it ug is going to make trp which is trypan so you would write trp the same thing with AGC so I'll do that one first we find oh here's a we know we're going to be in this row we find G our G is here on the end and then you find C uh C is here that's Siri s e r so those two are going to be sering I'll save the last one for you it's C AA I forgot the line in the middle um so again make sure you're very familiar with how to read these so um again let's talk about how to translate our mRNA uh we don't have too many slides here but I want to kind of walk you through that that process again um so we're going to start with bacteria it's just easier to understand so you get the basic concepts instead of talking about UK carots um so all of our mRNA is going to have a rib Al binding site so this is where our ribosome will bind so remember our ribosome is this little those little dots we would always see um this is where it's going to bind it is going to start at the start codon so this is going to be the first amino acid uh in the polypeptide sequence that begins with UAG right so you may have some some codons that come before it but we're only starting when we see the start sequence the coding sequence is all the area in the middle it's just all the other um codons in the middle and then finally our stop sequence or termination or nonsense codon is going to be the last one that contains these values so again there can be some after it but once we stop it we're done so we're only going from start to stop if there's codons on this side or on this side we're not worrying about it so again this is just showing you a real life picture right um and how the start codeon is going to Define some of the reading Fame frame so what we want to do here is anytime we see this we want to make sure that we can um you know Mark off our answer in threes and then once we do that we'll identify our first codeon and then transcribe the rest of the message um this is interesting because it's showing that one small change let's say a mutation somewhere can really mess this up so if it's a group of three and let's say I added a u here right on the bottom there's a u on the top there's not a u that shifts everything down and because they're red in groups of three that can change all the amino acids so that's why things like mutations can be very bad for us because it can cause a totally different protein to be made instead of what was originally supposed to be made all right so this is an example here that I want y'all to work out I'm going to put it up on the screen for a second so that you can pause the video video and work through it um I'm going to also try to help you and give you some steps steps number one is separate the the codons so automatically you want to start going along and and you know separating codons by groups of three second step is to find the start third step is to translate them right use the key below to translate them and the fourth one is to stop simple as that separate the codons find the starting codon translate everything in the middle and then stop so I'll give you about 5 seconds and I'll start this problem so you can pause it at this point all right so I'm going to start working on it if you've worked on it I hope you have the first thing we want to do again is to separate this message it's going to be helpful for us so we can really truly identify how everything is being read this is good because I'm probably going to try to trick you by putting a false Aug you see this right here if you didn't separate it you would have thought we started right there but we're not so we're going to separate all the way down step one step one is separate all the way down okay step two that's done step two find the start so know start is Aug it's saying met here but this is our start so make sure you always know that start it has it in green you kind of forgot but that's where we start so you find the AUG it's not here it's not here here here oh here we go so the first protein we're going to translate is met right here at the bottom C Au C we find C we find a we find U that's hist c a c a g l n g Au U GGA oh stop we don't care about the rest because we already stopped so these are going to be the amino acids that we made with this particular message met P kein Asar me if you got a question I said how many amino acids does this polypeptide make four what's the third amino acid in this sequence from the polypeptide you made glycine it is not the third one here because we didn't make this one right we only started on this part of the actual polypeptide make sure you understand that okay so follow these steps if you follow these steps when you get questions about the polypeptide you made right because this is the polypeptide you won't be confused make sure you understand that okay so again let's talk about the MRNA and um R RNA molecules that are involved in this process so mRNA is going to um give you the codon right it's going to be that that message that I just wrote on the top of the screen before this is going to give you the set of those three nucleotides so that's the green line here the TRNA like I mentioned before it is going to be the transfer RNA it's going to be what carries the amino acids but on the bottom of the TRNA there is something called an anti-codon this is the three RNA nucleotide that is anti-parallel to what we're seeing here so for instance a AA from our mRNA is going to have a TRNA that is anti-parallel or opposite of it forming uuu so this code for a AA it should make lysine let me go back so a AA it will make lysine lyss and if you see on this image here the uuu correlates with a lysy right so that's how we're kind of connecting everything together and then finally the rrna which is essentially your ribosome this is going to allow the TRNA and the MRNA to come together and it's going to accept it um and it h actually kind of helped to form the poly ti so think of like a ticket machine if you remember those let's say you want to a stream tickets you can put your tickets in there or even you know a cash acceptor if you put a dollar in there it's going to kind of pull in that code right here and allow it to be trans uh lated up top so again just kind of reinforcing that there's a lot of components we have here mRNA TRNA ribosomes which will represent the rrna in some of those transcription factors this is also a chart from your uh from your book which kind of describes it a little bit better if you want to review that and then also just kind of quickly highlighting the steps or stages of translation it has the same ones as transcription which would begin with initiation so first the MRNA TRNA and the ribosome come together elongation we go from start to stop and then finally termination everything um separates and then you have your final polypeptide which will then start its folding process and then be functional like we've talked about before again kind of showing the overall idea or at least big picture of what you're seeing so you begin with your DNA which is um anti-parallel 5 Prime to 3 Prime right you see the matching or the correlating nucleotides you transcribe that to make a mRNA molecule right we lost our T's it's going to be more similar um or at least we're going to have our U's instead of our T's you have your mRNA you first separate everything and then you're going to create your or find your start codeon you TR translate your start codeon until you get to your stop codeon you do that by using those anti-codons which are anti-parallel to the start or excuse me to the MRNA message here those trnas are going to then have the amino acid attached to them and you will eventually create a polypeptide that can be used to go through the folding process so looking at this picture talking out loud to yourself seeing if you can walk through each of the stages will be a great practice for you so as we close translation I wanted to bring up something that's extremely relevant for us especially at this day and age which is the new covid mRNA vaccine so as a reminder I am am an immunologist so I study our immune system so um outside of what we do for bio12 I'm pretty well versed with this information so I wanted to make sure I shared this with you so that you can be more informed citizens you can share this with family and friends and you can apply what we've learned in class to a true real life relevant scenario so conventional vaccines think of the flu vaccine work in this manner we take either a weakened pathogen so we've taken the flu and we've taken out proteins to make it um as strong and as infectious as it normally is so we weaken the pathogen we've either inactivated the pathogen so killed it or done some other manipulation to it or we just take a tiny piece of it called an antigen um and put that in the vaccine so either way all of these are different things that we can use to activate our immune system to get our immune system to recognize this as being foreign and then create antibodies or create an immune response so that when we come across the real flu we already have a lot of soldiers or antibodies in our body that can be used to fight it off this is why sometimes when you get the flu shot you feel a little sick because you're actually getting either a dead flu particle or a portion of the flu that will cause you to be sick this has worked for the flu but it will not work for something like covid-19 which is a lot more dangerous some people people if they get just a portion of covid-19 through an antigen or even the the weakened um pathogen that can still cause a lot of damage so we cannot use this normal method of vaccine generation instead we've used an mRNA vaccine so you just heard me talk about mrnas a lot so I want to remind you how this vaccine is different and how it works so what we've done as scientists is we've identified one of those Spike proteins on the SARS Co 2 virus once we've identified that protein we actually looked at the message so remember we've already just talked about the protein right central dogma right we have the protein before the protein you have the RNA and then before the RNA of course you have the DNA so now that we know what the SARS Co 2 protein looks like we we identified what the MRNA transcript or message would look like so because we know what the instructions are to make this protein our mRNA virus that we have now is where we give our own body cells this instruction this recipe to make the protein so the vaccine consists of mRNA which we can give to our own cells that are packaged through these lipid nanop particles which are just little fat um particles so your body won't destroy it before it gets to the cell once this mRNA message gets inside of your normal cell your normal cell will use its ribosomes to make little tiny spark uh Spike proteins these Spike proteins will then be in your body and you will recognize them as foreign because you made a protein that you don't normally have and you will create an antibody response to these Spike proteins that antibody response will allow you to make millions of antibodies towards covid so whenever you come across the real covid-19 um or SARS Co 2 virus you will have already seen these spikes because you made them and you will already have abundance of antibodies in your body to be able to to protect you so this is really bringing together a lot of stuff that we talked about by taking the MRNA from um the vaccine and giving it to your body this eliminates a lot of the damaging effects that you see here using your own body to make a little portion of it will not be as dangerous as taking a real portion of the actual pathogen um mRNA it's not going to get into your nucleus because remember all of this translation happens your cytool so you don't have to worry about the MRNA going into your own DNA and incorporating itself it's all happening in the cytool you're just taking advantage of the ribosomes in your own cells to make little small similar um spikes so that you can create an immune response so that when you come across the virus you can be more protected so I just wanted to kind of close on that thought because this is so relevant so critical that we are informed and I want you to kind of see how a lot of the stuff that we talked about in class and those concepts are really all around us we talked about that on day one how biology is just truly surrounded um surrounding our life so I wanted to just give y'all a little quick summary of how That vaccine works so when you're watching the news when you're talking to family and friends you can explain to them how this is less dangerous because you're not using the real virus how you're actually using your own Machinery by taking the instructions for the protein making that protein yourself then using um that protein to be displayed so that you can create an immune response um all of these things I just want you all to be informed so that concludes our lecture for right now um so make sure you review it you look at everything related to translation and if you have any questions save them for class