You literally explained in 12 minutes what took my Microbiology professor a week and a half to teach. The difference is that I actually understood the concept! I know this video was made years ago, but I cannot possibly thank you enough for taking the time to make it!
You are such a great teacher!!!!! Thank you sir :) Im an spanish girl studying biochemistry and I have just 100% understood the attenuation system due to this video... I wish every teacher and scientist in the world got your enthusiasm and teached that good. Thank you :) and remember that "teaching means learning again" !! :):)
Oh my god I love you. Biochem final on Tuesday and this is exactly what I needed. No one ever bothered to explain where these Trp codons were. This makes it immensely more clear. Thank you thank you
THIS WAS AWESOME! sad that I'm paying thousands upon thousands of dollars to learn this in dental school and this is appreciably better... for free. Thanks for your time!
THANK YOU SO MUCH!! I'm a second year biomedical and it is only because of you that i have understood the concept. I wish my teacher was half as good!! PLZ PLZ mk more of these!!!
thank you for this video.. it all made sense in 10 min of watching 2 videos.. over 1 hour of my prof trying to explain this and failing miserably.. thank you!
Wow, I have been struggling with this understanding for a couple weeks now and in your short two videos, I completely get the concept. The only things I think I had trouble wrapping my brain around were when you drew the DNA and RNA polymerase, but I'll go ahead and read up a bit more on it to figure it out and watch your video again. Thanks a lot for this! Really helped me out!
I simply LOVE gentics! Great explanation! Very clear and easy to follow. It's easy to believe you know the topic very well by listening to the way you explain it! To make is short - without a doubt, never have I seen such a good explanation! I used to think I know the process of attenuation. After seeing that vid I know that it's only now I don't just know it but also understand it! THANKS A MILLION! :)
Understood perfectly every single thing! Thank you! If used right after 'Gene Regulation, by bozemanbiology' (which gives you the simple facts,trp is after the lac) it's really useful to enhance what you already know.
I'll second edowny0606 here - missed this lecture at uni and the notes didn't make sense and this just saved my butt, exam in two days! booyaa!! thanks agathman!
If 3+4 pair, the stem loop that they form is an intrinsic transcription terminator. The stem-loop binds to a site on RNA Polymerase and causes it to stop transcribing there, before it gets to the coding region of the operon. This is how transcription ends normally in most genes in E. coli, but at the end of the gene instead of the beginning.
@Sbrenzen -- I believe it's read-through. That is, the ribosome moves along the RNA after the stop codon and starts translating when it reaches another start codon; this is how the ribosome translates the multiple cistrons in a typical polycistronic mRNA in a prokaryote.
@Sbrenzen No, the stem loop (if it's the 3/4 stem-loop) can terminate transcription, but translation doesn't seem to be affected much by secondary structure of the mRNA.
No, transcription doesn't automatically terminate whenever there are several Us. The stem-loop is important in the termination process. For one source with more info, there's an article at PubMed Central called "The functional anatomy of an intrinsic transcription terminator", by Schwartz et al. that gives some background (and more refs) in the introduction.
Yes, the ribosome is translating the leader region. And transcription is simultaneous; the ribosome is translating the beginning of the mRNA -- the leader -- while the rest is starting transcription. If regions 3 and 4 of the leader can pair, they form a transcription terminator. Transcription then terminates, and the rest of the mRNA (the part that codes for the enzymes involved in tryptophan synthesis) doesn't get transcribed.
Very helpful video. I have a Microbiology final in an hour and this cleared some stuff right up. You're drawings are easy to understand. You should get a tablet and make some flash videos.
RNA polymerase binds to the DNA and synthesizes RNA complementary to it. The ribosome binds to the RNA and translates it. They're binding to different molecules. If the RNA polymerase hasn't reached region 2 (in the DNA), then it hasn't made that part of the RNA yet. So the ribosome couldn't possibly get there first.
Many thanks! But I have a question: when transcription continues, can the ribosome start translation directly from the AUG codon at the beginning of the trpE? Is there a ribosome binding-site?
Translation isn't impeded much by secondary structure in the RNA. I suppose that the ribosome must be able to break hydrogen bonds between RNA strands as it passes through, but I'm speculating.
I'm so confused by this one little part - in attenuation when the ribosome is going through the leader sequence, you say if [trp] is high, the ribosome moves quickly through region 1 and when it's in region, it 2 blocks region 3 from pairing with it so region 3 pairs with region 4. What is the ribosome doing? Translation? Are the structural genes only transcribed if the leader sequence is transcribed and translated correctly? I thought in prokaryotes that the two processes could be simultaneous.
Sir, Query related to attenuation: how does d transcription end when the [Trp] is high i.e. as u said first it moves away quickly from region 1 of mRNA as theres plenty of trp in surrounding, then region3 is transcribed followed by region4's transcription & as they are palindromes & region 2 is not free region 3&4 form a stem loop....... Further i havnt understood from the point how the trancription has ended at 3-4 stem loop. Please sir explain me just this part in text format. Thanks.
I have a question.......when trp levels are low, even though there is no loop formation between 3 and 4 regions, doesn't the presence of U repeats cause transcription termination??
Thank you. I think when I retire I'll make more of these just for fun.
You literally explained in 12 minutes what took my Microbiology professor a week and a half to teach. The difference is that I actually understood the concept! I know this video was made years ago, but I cannot possibly thank you enough for taking the time to make it!
Thanks for the kind words. It's been a while now since I've been in the classroom, but it's still nice to hear that these videos have some value.
I don't know why my nucleic acid professor did not explain the concept in this way. It makes much more sense! Thank you so much!
You explained it better in 10 minutes than my professor did in 60. Thanks so much!
You are such a great teacher!!!!! Thank you sir :) Im an spanish girl studying biochemistry and I have just 100% understood the attenuation system due to this video... I wish every teacher and scientist in the world got your enthusiasm and teached that good. Thank you :) and remember that "teaching means learning again" !! :):)
Oh my god I love you. Biochem final on Tuesday and this is exactly what I needed. No one ever bothered to explain where these Trp codons were. This makes it immensely more clear. Thank you thank you
I wish the people that teach here at my university would do it as clearly as you do, this here seems so simple and beautiful!
really an excellent explanation. I am a first year medical student, and your presentation is much clearer to what we saw in lecture!
Thanks!
talk about a moment of epiphany!
Crystal clear explanation.
Thank you.
THIS WAS AWESOME!
sad that I'm paying thousands upon thousands of dollars to learn this in dental school and this is appreciably better... for free. Thanks for your time!
When this video was over, i had the biggest smile on my face because of how well i understood what you taught. Keep it up Sir :)
Oh my God, I wish you were working at my university!!! Your explanation is so clear and easy to follow, once again thanks a million agathman!
THANK YOU SO MUCH!! I'm a second year biomedical and it is only because of you that i have understood the concept. I wish my teacher was half as good!! PLZ PLZ mk more of these!!!
thank you for this video.. it all made sense in 10 min of watching 2 videos.. over 1 hour of my prof trying to explain this and failing miserably.. thank you!
Thank you! Have a test tomorrow and the book couldnt help me figuring out how attenuation is working. This helped me.
Wow, I have been struggling with this understanding for a couple weeks now and in your short two videos, I completely get the concept. The only things I think I had trouble wrapping my brain around were when you drew the DNA and RNA polymerase, but I'll go ahead and read up a bit more on it to figure it out and watch your video again. Thanks a lot for this! Really helped me out!
You are the man. Keep up the good work! My lecturer bores me to sleep. Kudos to you.
This helped me understand the concept so much more, I think I might pass my molecular biology exam now! Thank you :)
Thanks very much, you did a much better job of explaining it than my lecturer!
I simply LOVE gentics! Great explanation! Very clear and easy to follow. It's easy to believe you know the topic very well by listening to the way you explain it! To make is short - without a doubt, never have I seen such a good explanation! I used to think I know the process of attenuation. After seeing that vid I know that it's only now I don't just know it but also understand it! THANKS A MILLION! :)
Understood perfectly every single thing! Thank you! If used right after 'Gene Regulation, by bozemanbiology' (which gives you the simple facts,trp is after the lac) it's really useful to enhance what you already know.
Thank you so much for posting your videos, you've explained EVERYTHING so clearly and simply. This will sure as hell help me with my resit...
OMG THANK YOU THANK YOU THANK YOUUUU! I have my genetics exams in 5 hours and you just saved my life! Thank you!!!
I'll second edowny0606 here - missed this lecture at uni and the notes didn't make sense and this just saved my butt, exam in two days! booyaa!!
thanks agathman!
This is extremely helpful, very good explanation of how this system works.
If 3+4 pair, the stem loop that they form is an intrinsic transcription terminator. The stem-loop binds to a site on RNA Polymerase and causes it to stop transcribing there, before it gets to the coding region of the operon. This is how transcription ends normally in most genes in E. coli, but at the end of the gene instead of the beginning.
You explained this much better than my professor. Thanks.
Explained better then my lecturer, thanks so much!
Again, described really well. You have truly helped me understand this. Thank you.
@Sbrenzen -- I believe it's read-through. That is, the ribosome moves along the RNA after the stop codon and starts translating when it reaches another start codon; this is how the ribosome translates the multiple cistrons in a typical polycistronic mRNA in a prokaryote.
@Sbrenzen No, the stem loop (if it's the 3/4 stem-loop) can terminate transcription, but translation doesn't seem to be affected much by secondary structure of the mRNA.
Thank you so much!!!! This makes it so much easier than our biochem teacher makes it!
No, transcription doesn't automatically terminate whenever there are several Us. The stem-loop is important in the termination process. For one source with more info, there's an article at PubMed Central called "The functional anatomy of an intrinsic transcription terminator", by Schwartz et al. that gives some background (and more refs) in the introduction.
Thank you for explaining this process and clarifying my doubts about it! It was really helpful, keep up the good work, cheers!!
The best concept I got about attenuation. Thanks Allen Gatman
wow love it .. thank u very much
thnx sir....this video just cleared a lot of my doubts....i got so confused reading abt this in d books...bt ur explanation ws perfect....thnx a lot.
Yes, the ribosome is translating the leader region. And transcription is simultaneous; the ribosome is translating the beginning of the mRNA -- the leader -- while the rest is starting transcription. If regions 3 and 4 of the leader can pair, they form a transcription terminator. Transcription then terminates, and the rest of the mRNA (the part that codes for the enzymes involved in tryptophan synthesis) doesn't get transcribed.
This just cleared up every question I had about this. Thank you so much for this! You're going to be the reason I ace this upcoming quiz!
Thank you so much, I read this section and I was so confused this regulation and you finally clarify this. :D
Such a nice video...you explained it so well in such a short time....thanks a lot.!
You are a great professor. I hope you have tenure if you have it already!
Thank you for sharing! from a medical student at a top 20 school (and you beat my prof).
Thank you soo much for this video! I got so confused when reading about this in books
tomorrow is my exam, and thats the part i didnt understand :D nice work - saved me :D
Very helpful video. I have a Microbiology final in an hour and this cleared some stuff right up. You're drawings are easy to understand. You should get a tablet and make some flash videos.
Thank you so much, please do make more, It was very helpful, I have got exam on Genes and Genomics in a few days time =)
Thank you very much for your explanation, i finally get it. Greetings from The Netherlands.
Brilliant.. great style of explaining!!!
RNA polymerase binds to the DNA and synthesizes RNA complementary to it. The ribosome binds to the RNA and translates it. They're binding to different molecules. If the RNA polymerase hasn't reached region 2 (in the DNA), then it hasn't made that part of the RNA yet. So the ribosome couldn't possibly get there first.
This was a fantastic help. Thank you for the clear explanation.
Thank you for this video. It explains basics of attenuation perfectly! :)
Thanks...
@agathman Ok, I got it. I believed that ribosome blocked once reached the stem-loop. Thank you so much (and sorry for english mistakes) !!
Thank you very much! I found this confusing but you explained it perfectly!
thnk u sir it made me clear all my doubts abut attenuation in trp.operon..
This was extremely helpful, thank you so much!
thnk u very much sir it made me clear all doubts about attenuation...
How can the ribosome pass through the stop codon of the leader sequence and continue moving along the mRNA to the start codon of the TrpE gene?
Thank you, I wish my lecturer explained like this .
This video was really very helpful ...thank u so much 😀😀😀😀😀😀😀😀😀
thank you sir, for your clear and informative explanation, i hope you will do more videos about genetics.
i am professor of biotechnology. its very useful for me.
you saved my life. Thank you so much
He save my life too
Many thanks!
But I have a question: when transcription continues, can the ribosome start translation directly from the AUG codon at the beginning of the trpE? Is there a ribosome binding-site?
thank you so much for making this video!
Thanks, much clearer than my med school prof!
Thank you very much for the video. I have a question, IF 2 AND 3 make a stem loop, how can ribosome continue to translate the sequence?
Translation isn't impeded much by secondary structure in the RNA. I suppose that the ribosome must be able to break hydrogen bonds between RNA strands as it passes through, but I'm speculating.
@yorevolution He is my professor and my advisor. He definately knows what he is talking about.
Thank you so much, many many many thanks for your time!
@agathman Great! Thank you for your prompt reply! Now I wish my examinator ask me about attenuation!
Thank you so much, made it very simple.
I'm so confused by this one little part - in attenuation when the ribosome is going through the leader sequence, you say if [trp] is high, the ribosome moves quickly through region 1 and when it's in region, it 2 blocks region 3 from pairing with it so region 3 pairs with region 4. What is the ribosome doing? Translation? Are the structural genes only transcribed if the leader sequence is transcribed and translated correctly? I thought in prokaryotes that the two processes could be simultaneous.
Thank You this vid was a GREAT help for me
Thank you very much, really good explanation :)
Sir, Query related to attenuation: how does d transcription end when the [Trp] is high i.e. as u said first it moves away quickly from region 1 of mRNA as theres plenty of trp in surrounding, then region3 is transcribed followed by region4's transcription & as they are palindromes & region 2 is not free region 3&4 form a stem loop....... Further i havnt understood from the point how the trancription has ended at 3-4 stem loop. Please sir explain me just this part in text format. Thanks.
Thanks alot!!! really good explain, great job
That helped. Thank you soooooo much. Thanks alot. You explained it so nicely. Thanks again :) :)
good work allen....... keep it up
That was AWESOME!!! Thank you, you rock!
Thank you! That makes better sense to me, now.
Excellent video! Thank you very much :)
you really helped me! thank you so much! good explaination
I have a question.......when trp levels are low, even though there is no loop formation between 3 and 4 regions, doesn't the presence of U repeats cause transcription termination??
Wonderful !! nice explanation
Thankyou very much, explained very well :)
Thanks ,clearly understood!
Ah Thank you! I finally get it now.
amazing! REALLLY helped!
thank you.. it is even fun to study such a mechanism
fantastic explanation
@sDlF309 -- Sorry, I should really put the logo on my vids or something. I'm at Southeast Missouri State University in Cape Girardeau, MO.
Thank you very much!!! very helpful!
you sir are brilliant! Thanyou so much!
Superb Explanation
great video, so clear! :)
finally i understood .... thank you so much
Yeah, finally i can understand, thanks!! :)
this is so helpful....thanks..
Thanks Allen
--Royce
Excellent! Thank you so much! :D