This guy has been helping since I was a freshman in high school... I am now about to graduate college

can not believe how much more helpful you are than my professor. god.

sal from khan academy makes me feel safe

you just compressed 3 of my agonizing lectures into 11 minutes and now i've understood it all. You are my hero.

This helps me understand the LAC OPERON very well without bordering reading whole Campbell 10th edition textbook.

Thanks for this video! Great explanation! One thing to add for those who are curious is that when glucose levels are high the RNA-polymerase will bind to a promoter (not the same promoter) and transcribe a gene that codes for a repressor so that in turn can bind to the operator and stop transcription of the beta-galactosidase (LacZ) since we don't need to metabolize lactose.

I love this guy. Whoever is the narrator. Amazing explanation. He just made lipincott so easy. Khan Academy is the best. Always listen to it literally for every topic

Thank You Khan Academy, What took Hours of Learning you taught in 11 minutes, Thanks!

This is so much better than trying to read from the Lehninger Principles of Biochemistry textbook. I read every word about the lac operon, but did not understand any of it until this video. THANK YOU

Yesterday, I went to my professor to ask him this exact question. I wish I didn't go. this video. saved my life. Thank you so much

I referred your videos for taking a biology seminar at my school and i got an A+, thank you khan academy.

I used to watch your videos in high school/mcat. Now im months away from my usmle step 1 in final year of medical school and youre still helping me. Thankyou

This is the first time I actually completely understood the chapter of molecular inheritance, thank you so much khan academy

Unbelievably helpful, took a concept that I wasn't understanding from lecture and made it make so much sense

Learned more in 1 video than an entire week of class

I am a MS2. This video still teaches it better than my biochem or microbio prof. Thank you!

This was one of the best explanations of the lac operon I've heard

sir there are no words to say for your effortless work I have so much respect fr u KEEP INSPIRING !!

I decided to take Microbiology over the summer, for the 6 week term. I don't even bother listening to my lectures anymore because they are so confusing and overly complicated. I just use my book along with Khan Academy. I will be making a donation!

I love this man. I love his personality and the fact that this stuff is less boring and more easy to understand now.

Especially that you explained the cAMP was very helpful. I'm german and I didn't find anything about it in german videos. Thank you!

I think I’ve watched this video minimum ten times over the course of my degree

superb, I m Ms genetics student and having this topic in molecular genetics, very impressive. Stay blessed

My professor spent two lectures trying to explain this and we were all still blank at the end of it. Thank you so much

Wow! I've skipped over this many times. Thanks for making is so easy to understand!

You cracking up made this a very enjoyable learning experience for me. Thanks

Sal you are a life saver.

One hour study in 10 min!! thank you!!

Love you guys! Paying a fortune for MD school to come here post lecture to learn the material : ))))

This is SAVING my life. Thank you so much.

Why can't professors explain this as easily?

Thankyou so much! I have paper tomorrow and watching your video really helps me to understand the concept. You're my savior

I would like to point out that the Operon is activated when glucose is absent and lactose is present. If glucose and lactose are present, the repressor would still remain bound

Seriously u are heavenly teachinggg... thank u so so so very much ! All the best ,keep helping us ]

SO GOOD, EXPLAINS BETTER THAN ANYONE ELSE COULD

I’ve been trying to understand this for weeks 😂 thank you

i will ace this question ,in my exam tomorrow,all thanks to you

"catabolater" made me laugh, thankyou now this can finally stay in my brain 😭

To sum up, when there is no glucose and lactose is present, the catabolite activator protein with high cAMP will bind to the CAP site, therefore enabling transcription(the body needs energy) while if there is glucose and lactose, the system prefers glucose over lactose and will not transcribe. The catabolite activator protein will not bind since it already has a lot of cAMP, here the lac operon acts as an regulatory sequence of gene responsible for protein synthesis. The glucose inhibits the production of cAMP(cAMP are derivatives of ATP) which makes sense since there is already a lot of energy.

best 11 minutes of my life

Great explanation. You just saved my life❤

Thank you so so so much, I didn't understand the Lac operon until now. You saved me!!!

The explanation is very good. It helps me a lot nunderstanding the topic correctly. Thanks Khan Academy

Amazing set of videos... easy to understand and very helpful...

You're doing a good job, better than most of my french university teacher

this video is just perfect to understand ! just amazing ! hope you'll continue these kind of videos thank you so much

As a suggestion I think you should have a quiz after every lecture

Wish i had known about this guy when i was still in high school

Thank you so much for helping me understand how Lac operon works!! I didn't even understand the mechanism when my professor told us in my native language

this sounded so complicated when my teacher taught it ! tysm !

Thanks a lot for this video and also the one on tryptophan. I was understanding nothing about this genetic expression regulation systems, and you made it very clear, I feel I completely got it. You explain very well and the video also helps So thanks and keep it up :DD

Khan da real MVP

thank you very much SIR the way you explain the topic makes it very clear i understood very well THANK YOU AGAIN

I've watched so many of your videos to save me from failing. At this point, I owe you my college tuition.

U r saving me everytime😌no other videos satisfies me in studying

this is AMAZING ! thank you so much and keep please don't stop posting vedioes

My microbio professor warned me not to use this video as a resource to study, she says its wrong. Khan academy is a good resource but this particular video may not match some undergrad classes. Viewer beware!

This saved me, thanks!

SHORT and SWEET, thanks prof

gosh it's just so much more useful than my teacher

Seriously, u are the best...💪

god bless u. ur saving me from vandy bio

thank you I'm studying for Micro final and this helped a lot

Amazing explanation❤

THIS. IS. AMAZING!!!!!!!!!!!

OMG. Thank you so much! I can't believe how much better you are explaining that then my uni lecturer! I mean even in english (I am from Germany) I can easily understand what u are talking about. You saved me. Hopefully trp will be as good as this video. =) Keep going'! Best Regards

FINALLY!!! I really needed to understand this, thank you!!!!

Awesome explanation and has made life so much easier, thank you!!

this guy sounds like Dave Smith, AND is also a good teacher. lol, awesome

i honestly love you bro.

You are seriously the best!!!

Amazing video guys. Thanks a lot for the help.

Thank you so much! You’re truly a life saver

this saved me

sooo helpful, you made it easy, thanks a lot

Thanks a lot

Very well explained thanks!

Super helpful as always!

thank you so much for letting me understand

thank you so much

You guys are great. Thanks!

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Thank you very much! It's really helpful!!!

Excellent

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Thank you soooo much

Great video. Thanks.

wow,, it helps me so much,, thank you!!

thank you for this video 💚💚💚

omg this is a life saver

So you lack the lac operon

Thank you so much Sir !

This means if you are lactose intolerant and still want to drink milk, do it when you have'nt eaten anything all day.

thank you so much. it helps a lot♥️

Thank you 🤓🤓 It was a huge help 🤓🤓

Thank you so much!!

Super! Thanks

thx very much salman khan even you are a star man

Drop the mike Sal, great video.

thanks man