Andrey, really appreciate your videos; specifically writing down the sequences and showing with different colors really makes it easy to understand. Thank you very much!
Great videos! Your teaching style is exceptional! They definitely clear up many of my questions in my readings. However, I did have one question pertaining to this. When you say that DNA ligase is added to combine the two sequences of DNA and form the recombinant DNA, how do you make sure that DNA ligase doesn't just form the two original circular forms of DNA?
I am probably too late to reply but... A phosphatase comes to take dephosphorylate the plasmid (so it doesn't reanneal) When the gene if interest comes along, it binds to the plasmid by its phosphates.
thanks a lot very well understanding..but I have a question, we say that bacteria use these restriction enzymes to digest the viral dna when infected by them and before doing that uses methyl transferase enzyme to protect it's dna from these restriction enzymes...my question is, are these enzymes always present in bacterial cell or they will be produced up on infection??? is there any mechanism for that ?? best regards
Mustafa Fahmi انا كنت هسقط اقسم بالله لولا الفيديوهات بتاعته !!! رهيب نجحتي فسنه اولي و سنه تانيه طب فمواد البيوكمستري و المولوكيلور بيولوجي و الهوريزونتال جين ترانسفير !!! عبقري !!! يستحق فلوس الدراسه مش الجامعه و الله
DONATED !!! Today I passed the final exam successfully in the subject of “ Horizontal Gene Transfer “ in medical school because of your video lectures !!! I can’t find the words to thank you honestly!!! Without you , I would have been lost or failed!!!
Very nice video, thank you :) I think there is a mistake though. The 5' and 3' sticky ends do not match in the upper left drawing and lower left drawing.
One thing I don't understand.... What makes the sticky ends of the two molecules bind to each other rather than just close their own molecules again once the DNA ligase is in the mix?
Using this exellent videos of you , i can make more effective my studying and it takes to me less time to clearly understand things. I just wanted to thank you for your contribution to community, especially to students!
The ligase can rejoin the original DNA strands as well as it can form recombinants, which can be identified and separated by some techniques. To avoid self ligation of the DNA molecules, an enzyme called Alkaline phosphatase can be added to the DNA fragments before ligation. This enzyme removes the 5' phosphates from the DNA segments. Now the DNA fragments can only attach through h- bonding between the sticky ends of the DNA molecules. Inside the bacterial cell The DNA repair systems join the single stranded nicks. The recombinants can be purified later.
I'm a bit confused here so excuse me if my question is stupid, but in case we want to obtain genes that could be later used for medical purposes, we have to make cDNA first out of humain genes and then insert it into plasmids, right ?
im wondering, if the plasmid dna is bound to have multiple sites were the restriction enzyme will bind? because of the sheer number of base pairs? if this is the case, how do you ensure that the restriction enzyme will cut at the right place? you have some great videos my friend
Thank you! I keep reading my book and looking up each section in your videos because I can't understand my book. Thank you for your great illustrations and repetition. You have a gift.
just 2 minutes into ur lecture I had to pause the video and Comment on how informative this video was !!! This is amazing! I loved it ! Thank you so much, & keep doing what you do !
I'm seriously mind blown now..like all these were really confusing but after hearing this lecture everything connects and makes sense..Thank you so much
Well..i.understand that the enzyme breaks open the dna strand between A and T base pairs in a dana molicule of a palindrome sequence ..but during a dna recombination what if the othr molicule did not have any palindrome sequence on the whole...or if it did not the the same palindrome sequence as the first one...can recombination take place during such conditions??...can such conditions arise in reality??....nd yet anothr doub of mine is that ..will the cut in a palindrome sequence take place only betweeen A ND T pairs?? if yes .then taking the palindrome Sequence as A T A T A T now where can the T A T A T A Cut take place
