How to Translate mRNA to Amino Acids (DECODING THE GENETIC CODE)
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- Опубликовано: 24 мар 2023
- DNA makes mRNA makes protein, and to figure out what protein a specific sequence of mRNA creates we can use a codon table. Today I’ll show you how!
The genetic code consists of 4 bases which code for 20 amino acids. The nucleotides in the mRNA are read in triplets, called codons, which means that the total number of combinations are 4 to the power of 3 or in other words 64 possible combinations. So we can read a mRNA strand from the left to the right in groups of 3. Each set of 3 or in other words, each codon codes for a specific amino acid.
The mRNA can be interpreted using a codon table or a codon wheel. We will use the same strand of mRNA in both cases for simplicity to make sure you understand the idea. Before we do anything else, we need to find a start codon and a stop codon. From the table, we can quickly notice that the start codon is AUG. The stop codon will either be UAA, UAG or UGA. For some reason thinking about a cave man helps me remember all 4 of these start and stop codons…. The space in-between the start and stop codon is known as a reading frame.
So starting with the codon table we simply read it from the left to the right. The start codon codes for methionine. The second triplet is UGC. By looking at the table here, here and here we can see that the second amino acid is cysteine. Then comes AUC, now we look here, here and here to see that the next amino acid is isoleucine.
The codon wheel is almost even more intuitive. You simply read from the center outwards. Let’s use the same example to read out the final 2 codons. So next comes CCA. By simply starting from C, going to the next C and all the way out to A, we see that the next amino acid in the chain is proline. The final codon is UGA, which you might remember since it sounds rather “cavemanlike”. Anyway, let’s read it out just to ensure that we know how to use the wheel as well. So we simply read, U to G to A to find this little square which if we look here we can see means stop.
Congratulations! You know how to use both a codon table as well as a codon wheel to successfully translate mRNA into amino acids.
Let me know how I can improve! I want to become a great teacher and I need feedback to improve!
You are a life saver! Made this super simple! thank you!
Fantastic to hear!👍
you explained it very clearly, it helped me a lot. Thanks:)
Fantastic to hear!👍
This was very simple and easy! Thank you very much.
I'm glad I was able to help!😇
this wasreally helpful! thank you
Thank you for taking the time to write such a nice comment♥️
Thanks it helped a good bit :)
Happy to hear that! Thanks for taking the time to comment🙏
Perfect! Thank you
Happy I could help!👍
awesome! rhanks so much
I'm happy you found the video helpful😇👍
Needed to stuff all this information into my head for a test cause I procrastinate lol
I know the feeling. I'm obsessed right now about creating a really cheap product that could help with more efficient studying, motivation and beating procrastination. I'll most likely try to have a minimum viable product ready before the end of the year so stay tuned for that if you are interested!
Or if these videos are helpful enough, just stick to them ;D
Thank you,
Thank you for watching!😇
Please make a video on how to learn them.
Good suggestion, thank you!
How can I translate a case where the mRNA has insertion mutation? And can you explain how does it affect the proteins?
Then the codons will change. For example, in AUGGCGUGGAGA, We'll get in sequence Met-Ala-Trp-Arg and more if there are more sequences, but if we add A at 8th position of the sequence, we'll get AUGGCGUGAAGA, then the sequence will be Met-Ala and not code further cuz UGA is a stop codon. Hope you understand.
Great answer! Thank you🙏
So I only start on a start codon and I stop on a stop codon? Or do I start a new codon after I see stop? What do I do with the extra nucleotides?
Correct! You do not use the "extra" nucleotides when translating that section. If you encounter a STOP codon you do not start again until you see a new start codon😇
And remember to read in triplets after you encounter the START codon👍
@@biotechlucas4126 ok got it tysm!
Trick to learn a codon table please
Wait, do you mean learn it by heart? Any reason why you would want to do that?😇
For the entrance exam which will be in 10 days
@@Nidhijaglann You need to know it by heart for an entrance exam?? What a silly requirement!
Well, I'll see if I can come up with anything to make it easy. Honestly I think you're best bet is to try to draw the wheel shown in this video enough times that you learn how to do it without having to look it up.
Once you've drawn the wheel, you can use it in the way I described it in the video to answer any and all questions related to to it! I'll spend some time thinking of a way to learn it easily😇
@@biotechlucas4126 ahh yes well it is in the core book from where they ask questions there are chances of it being asked I don't wanna loose my chance for selection
@@Nidhijaglann Well, one thing I'm noticing is that the wheel is just GUCA around and around so if you now where to start it becomes very easy.
Then the more difficult part is to remember what amino acids go where. I'd try and clump them together, 3 by 3 or 4 by 4.
So starting from straight up you have Phe-Leu-Ser-Tyy, then Stop-Stop-Cys-Stop and so on.
As a general rule I despise memorization without understanding and especially when it's something as easy to look up as the codon table/wheel but if my life dependent on it, this is how I'd do it!
Good luck!
This is confusing
Sorry to hear that. Is there something in particular that I can clarify for you?😇
@@biotechlucas4126how does the chart convert to writing because the chart is what I listened in science class living environment and I don’t remember the circle thing if that made sense thanks for replying imma subscribe
@@swishstudios285 Do you mean how you convert from DNA to an amino acid chain? Well you read the chart from LEFT SIDE - UPPER SIDE - RIGHT SIDE, and the only amino acid that all 3 codons will overlap is your amino acid of interest. Let's say your codon is CUA, then it's the SECOND on the LEFT SIDE, the FIRST COLUMN on the UPPER SIDE and the 3rd LETTER on the second row on the right side.
The corresponding amino acid is Leucine which is shortened as Leu.
In other words, we simply use the chart to find the correct location of what we are looking for but if you happen to see the codon (3 DNA nucleotides) that you are looking for, you can just check the corresponding amino acid (the one next to the codon) immediately and forget about the "proper way" to find what you are looking for.
I hope that is of some help!