A2 Biology - Lac operon (OCR A Chapter 19.2)
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- Опубліковано 18 тра 2018
- Lac operon is a group of genes often found in prokaryotes, which is only activated when lactose (instead of glucose) is available as a respiratory substrate. Here we will discuss how the regulatory and structural genes and other substances interact to produce enzymes to metabolise lactose. Keep in mind that even though eukaryotes don't have the lac operon, we do have regulatory and structural genes. Make sure you can identify them in exam questions on eukaryotic gene expression control or epistasis based on the information given!
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You just made a very confusing and horrific process much less horrific and much more simple! Life saver!
Absolutely loved this video, the books explanation was too wordy whereas you've broken it down and now I am able to just write these steps and learn from it. Thank you so so much !!!
You're saving me in online school right now!!
Here are some notes too.
ua-cam.com/video/YSvoid3wjbc_/v-deo.html_THE_LAC_OPERON
Hi, I just wanted to ask, do you cover every spec point that we need to know for OCR A Biology in the videos or are some of them extra? Thank you so much !!
Wow, I understand it now. Thank you - so clear!
YOUR VIDEOS ARE SO HELPFUL!!! you explain things so well!! thanks so much
Finally understand after looking at my textbook, CGP and snap revise!!!! Thank you so much
Your notes are amazing and the way you explain is so simple and straight forward. Thanks, keep up the good work! :)
Thank you! Glad that you find them helpful :D
this was MASSIVELY helpful thank you so so so much
haha glad you find it helpful! :D Thanks for watching!
Such a great explanation!
Glad to be of help! Thanks for watching :)
Life Saver !!! Thank You !!!
thank you for your videos I am really grateful. Did you hear when you talk, there is constant cutting of your voice. In other videos it wasn't this much. have a great day!
ok best explanation ever ....
thank you for the video! i understood it very well but do I need to memorise the 3 enzymes the structural genes make for OCR A?
No, they are unlikely to ask that...! Thanks for watching!
Hey thank you so much for the videos, they have been really helpful. In all my books it shows the promoter comes before the operator, in your video it is the other way round, I was wondering if the position matters??
if you have the ocr book they had the diagram the wrong way round
I wouldn't worry about the positions that much. The key thing to know is how the repressor binds to the operator which subsequently prevents RNA polymerase binding to promoter and working properly to read off the structural genes. Hope this helps :) Thanks for watching!
loved the demo :)
haha me too! ;D
really helpful video thank you so much i get it now :)
Thank you so much! life saver!
Glad you find it helpful! Thanks for watching :D
is rna polymerase synthesising the mrna or the actual enzyme proteins? im just a little confused because it sounds like they skip the ribosome stage
RNA polymerase catalyses the formation of phosphpdiester bonds between RNA nucleotides to make mRNA. The mRNA then goes to the ribosome to make a polypeptide chain. In this particular video, I was focusing on the control of gene expression hence I didn't mention specific the process of translation. Hope this helps! :D
great vid, how are genes regulated in eukaryotes is it the same process?
Operons (as a group of genes) only really exist in prokaryotes. In eukaryotes, it will be different levels of transcriptional and translational control. You might find it helpful to refer to the other videos in the playlist :D Thanks for watching!
Your videos are great but the order is “promoter then operator” the OCR books have made that mistake on the diagram by putting operator and then promoter. When its the other way round.
Yes I eventually realised! Sorry about that... hopefully you still know the key point is that the repressor protein prevents the RNA polymerase from binding/working successfully, hence no transcription of the structural genes... Thanks for pointing it out and thanks for watching! :D
THANK YOU!
Haha thank you for watching!
Thank You!
Thanks for watching! :D
do we need to know the name of the enzymes that lacZ, lacY and lacA code for?
I am not entirely sure, but I think it's probably best to learn them just in case. It does help understanding how lactose is processed/used. However, if it takes way too much effort to memorise them, I'd say direct your efforts to learning the rest of the content. Seems like a much better use of energy lol
where does cAMP come from and when does it becomes available in the cell of the ecoli
Riane Bekhedda camp is atp which has been converted
thank you!!
Thank you for watching :D
Welcome
AMAZING
Isn’t the promoter and operator the other way round?
Yes!
I just noticed that the at 3:20 operator should be after promoter, it’s an error made by ocr it should be the other way around
Yes it is!! I only noticed it afterwards so couldn't change it but you are correct :)
I love u🫶🫶