The Trp operon demystified

[@steveholmes1736]

This is the best explanation of the tryptophan operon I have ever seen! There are no textbooks, there are no videos, there’s simply nowhere else we’re such a clear, concise and understandable explanation of the tryptophan operation is given. Please make more videos.

[@andrewdouch]

Thanks for such a lovely review. Glad you found it helpful.

[@oliverhair3618]

Crazy that I did this in Year 11 and now coming back to this video as a first year Biomedical Science student, this video is so detailed and clear! So helpful, thank you!!

[@saramr-ingur6220]

You, kind sir, are absolutely saving my degree!

[@DamithaSaththiyananthan]

I was looking for a video explaining the trp attenuation. Other videos were too short to explain everything in detail. With your explanation every step makes sense. Thank you so much!!

[@andrewdouch]

I'm really glad to hear it helped you

[@katenicholls5301]

Your joy in this matches mine. I love your classes, and I'm so happy to have found your mega-helpful site. Thank you.

[@andrewdouch]

Glad you like them!

[@cosdogy7777]

Andrew the legend! Thanks so much for helping me with VCE bio!

[@TheBrandedAffiliate]

Love this!!! Your edrolo lessons have helped me develop a love for biology and helped me enjoy school more thank you so much! Keep making this awesome content!

[@raymorr_12]

Coming from the online presentation you did recently, this was great to cement that information, thank you!

[@andrewdouch]

Glad it was helpful!

[@hashifahizzatinadifan8872]

Thank you so much for explaining why the ribosome doesn't need to pass the hairpin!

[@malikbenmoumen5878]

I'm a biotechnology student, 3rd year Licence (frome Algeria). I'm having an exam of a module called Genetics éléments of micro organisms. This video really helped me to understand trp operon regulation. Thank you!

[@andrewdouch]

You're welcome - I'm glad you found it useful!

[@malikbenmoumen5878]

@@andrewdouch what a coincidence. I was just watching the video you made about human insulin synthesis. Which also I found pretty useful. Thank you for another time!

[@davidkommineni1863]

i love you douchy

[@midotah]

I have just one question, how is it possible that an explanation of such clearness and wonderfullness cant reach 182 million likes, if not more, in the same time other videos in youtube reach more than that, I rearly admire the way you explain this topic, I am saying this because I spent all the moorining looking for a video that explain TRP operon and atenuation process, and yours was so.... thank you

[@andrewdouch]

thanks for that - I'm glad you liked it. I guess trp operon is not as popular as some topics people make videos about.

[@sampatel6370]

exams are around the corner and this helped a lot... thanks 😶‍🌫🤩

[@andrewdouch]

Happy to help!

[@resonancerecordings]

Best explanation for this mechanism on KZbin! Thanks a lot!

[@andrewdouch]

You're very welcome!

[@farhanjamil8414]

Damn it! This is just awesome. Thanks man.

[@sophiedahlenburg156]

Hello! Year 12 biology student here, quick question - just wondering why the stop triplet in the dna of the leader section does not cause RNA polymerase to stop transcription? because the stop codon causes the ribosome to stop translation, so how come the RNA polymerase can continue transcribing the mRNA past this? hope this makes sense, and thank you for all your awesome resources throughout the year :)

[@andrewdouch]

Start and Stop codons are for ribosomes, not polymerases. RNA Polymerase starts transcribing at the promoter and ends at a terminator sequence in the trailer region (3’ UTR).

[@courtneysimons3344]

Well done Andrew!

[@andrewdouch]

Thanks!

[@manashpratimdutta2923]

Please make more videos... you are amazing

[@ehtishamkhokhar9588]

Excellent !!!

[@ethangilmore9655]

Great video, thank you!

[@gabrielazimbron7161]

Great video-- thank you! I've got a follow-up question: If there are ribosome binding sites and start codons at the start of the structural genes, doesn't that make the attenuation part of this whole thing meaningless? The way my textbook explains it is that the whole point of the attenuator is to stop the ribosome from being able to continue on from the 5' UTR to the structural genes and translate them. It has no mention of the stop codon after region 1. Thanks!

[@gabrielazimbron7161]

I answered my own question I think....the purpose of the attenuation is to determine whether the structural genes get TRANSCRIBED. In the case of the attenuation, the RNA pol. is "kicked off" the DNA, and the mRNA corresponding to the structural genes doesn't get made and therefore cannot be translated. If the attenuation does happen, the other ribosome being stopped doesn't matter because ones the structural genes are transcribed into mRNA, they have the hardware to recruit ribosomes for translation. Typing this out helped me study! Thanks!

[@andrewdouch]

Exactly. It is *transcription* that is attenuated-translation continues normally. The entire operon is transcribed into one RNA by a single RNA polymerase, but then each of the genes in the RNA is translated separately by ribosomes. But if transcription is attenuated at the end of the leader sequence, there are no RNA copies of the structural genes for ribosomes to bind to.

[@gabrielazimbron7161]

@@andrewdouch Thanks so much for replying!

[@thespinodino1682]

Great Video 😀

[@andrewdouch]

Thanks! 😀

[@joranerobert7154]

Wow! Amazing explanation! I hate memorizing steps in biology, there is a reason behind each steps and you were able to fill the missing information! Now, on the test, i will go based on logic, rather than relying on my fish brain!

[@andrewdouch]

I'm so glad that you found it helpful. Good luck on the test!

[@iPodCharger69420]

28:23 the what lings andy?

[@JesahEmmanuel]

Very educative 🙌

[@paddyobrien4321]

Hey Andrew, was wondering whether or not the trpL sequence (region 1) encodes mRNA that becomes useful in the cell? If so, then what does it do?

[@andrewdouch]

Hi Paddy. It encodes mRNA but it's not used for anything. The only function of the mRNA from the leader is for attenuation

[@paddyobrien4321]

@@andrewdouch Thanks!

[@HảiAnhTrần-x5v]

i hav a question Why does the ribosome not leave even though has met the stop codon

[@andrewdouch]

It does leave, but it's not like it just hits the stop codon and falls off; instead detaching from the stop codon is a bit of a process and requires a number of release factors (proteins) to be co-opted in sequence. All that takes a moment, and in that moment the ribosome is sitting there covering part of region 2. BUT even if it does detach quickly, there's a backup plan! Part of region 1 is complementary to part of region 2 , so if the ribosome detaches, 1 and 2 form a hairpin loop, which still prevents 3 from forming a hairpin loop with 2.

[@NoName-rr3zh]

thankyou so much! this is a such an intresting process

[@andrewdouch]

Glad you think so!

[@THA2001ALZ]

بارك الله بك شكرا جزيلا

[@VasilevArtem-g4u]

Thank you. helped me damn lot

[@blndazad5541]

thank you sir

[@andrewdouch]

Most welcome

[@Hornet-bz4xg]

Chadly beast