oh my god, I couldn't understand this for weeks,I couldn't find any good explanatory videos and you just answered all my questions. I have my biochemistry exam on Monday. thank you
@Leah4sciMCAT8 жыл бұрын
thank you! glad to help Good luck on Monday!
@khazeemahafeez68116 жыл бұрын
You are truly gifted when it comes to explaining MCAT content. Thank you!
@Leah4sciMCAT6 жыл бұрын
Thank you for your kind words!
@Josh_Morales Жыл бұрын
Thank you so much Lea! I was struggling with this and got a 503 MCAT, now I ended up getting at 517 and will make a video about how I did it! Thank you so much!
@Leah4sciMCAT Жыл бұрын
That's fantastic, congratulations! And yes, make that video and help others see how they can reach their goals, too!
@carolpena10752 жыл бұрын
I can't express how greatfull I am. I've been trying to understand those concepts for weeks with my regular teacher and failed miserably. This explanation was so clear, i finally understood!! Thank you so much!!
@Leah4sciMCAT2 жыл бұрын
I'm sorry you've had such a struggle with it, but happy that I was able to help you understand!
@jessicahoff85743 жыл бұрын
Just brilliant. Will be sharing with my past BioChem professor (she loves solid educational videos - knows students all have different learning styles) along with my Pre-Med base. Regret not thoroughly watching through these years ago.
@Leah4sciMCAT3 жыл бұрын
Please do, and thanks for sharing!
@RahulGupta-uk7xy3 ай бұрын
This concept help me to crack jee advanced 2020 question in seconds ❤❤ 👍 thanks 😊
@Leah4sciMCAT3 ай бұрын
YES to saving time on exam questions!
@myamitchell8675 Жыл бұрын
You are just so amazing Leah! You have assisted with turning the cogs in my brains just that little bit more every time!
@Leah4sciMCAT Жыл бұрын
I'm so glad to hear that I've helped it all click into place!
@Biotechnologynerd3 жыл бұрын
I'm Really thankful to u for making this tutorial.. finally understood the concept 👍
@Leah4sciMCAT3 жыл бұрын
Happy to help!
@rampalepu92318 жыл бұрын
Excellent job! I totally understand it now. Thank you so much.
@Leah4sciMCAT8 жыл бұрын
+Ram Palepu You're very welcome! Glad to help
@brandonherron45893 жыл бұрын
Your voice is like ASMR, It's relaxing and soothing. I like it a lot, ever think about doing deep sleep mix tapes? 🌝
@Leah4sciMCAT3 жыл бұрын
hahaha, I haven't, but thanks!
@sophiemay29334 ай бұрын
I think you may have just saved me from a meltdown. Thanks ;)
@Leah4sciMCAT4 ай бұрын
Glad I could help keep the meltdown away! Might I suggest booking some time just for yourself for a walk, bath, reading or something else enjoyable where you can completely unplug? Even 20 minutes can make a huge difference.
@mesvetnova78364 жыл бұрын
You explain everything thoroughly! Very good videos. I've recommended this to other students
@Leah4sciMCAT4 жыл бұрын
Thanks so much, I really appreciate that!
@asiakhatoon9543 жыл бұрын
Thanks a ton, this concept was troubling me from past 2 days 😇😇😇😇thank you thank you thank you for making it crystal clear.
@Leah4sciMCAT3 жыл бұрын
Glad it helped! You're very welcome!
@rustybolts89533 жыл бұрын
Don't understand everything yet but very clear explanation and presentation. Thank You.
@Leah4sciMCAT3 жыл бұрын
You're very welcome! I'm glad it's helping to clear things up. Go back and rewatch a few more times to help solidify the concepts.
@AR-vb4xy4 жыл бұрын
Just found this channel of yours right now! Keep up the good work Leah!!
@Leah4sciMCAT4 жыл бұрын
Thank you so much!!
@daaiibrahim16523 жыл бұрын
OMG THIS IS AWSOME , I was so confused, you broke it down so so so well!!!!
@Leah4sciMCAT3 жыл бұрын
Thanks so much!
@sowhat14443 жыл бұрын
THANK YOU OMG THANK YOU!!! YOU SAVED ME! IM SO GRATEFUL FOR THIS CHANNEL!!!!
@Leah4sciMCAT3 жыл бұрын
You're welcome! Happy to help!
@brokensymmetry18745 жыл бұрын
It finally made sense to me while looking at Le Chatelier's principle! Thanks!!!
@Leah4sciMCAT5 жыл бұрын
Glad the video helped! You're welcome :)
@mohammadal-shamasneh26642 жыл бұрын
What an AWESOME explanation!! you have just lightened my road 😃thank you very much .
@Leah4sciMCAT Жыл бұрын
You're very welcome, so glad it helped!!
@ahmedelyamani60492 жыл бұрын
you're the best, thanks a lot.
@Leah4sciMCAT2 жыл бұрын
Awwww, you're so welcome!
@n.i2887 жыл бұрын
Saved me once again ❤ thanks for doing what you do!
@Leah4sciMCAT7 жыл бұрын
You're very welcome! Glad it helped :)
@lili1596xd7 жыл бұрын
thank you so much i struggled so much with this topic
@Leah4sciMCAT8 ай бұрын
It's a tough topic, happy to help!
@vichuang2735 жыл бұрын
Thanks to this wonderful video! But I still don't understand that why -COOH is still -COOH after protonation and also why CH3NH3+ is still CH3NH3+ after protonation?
@Leah4sciMCAT5 жыл бұрын
At which specific point in the video?
@mesvetnova78364 жыл бұрын
Because -COOH is already a protonated form of carboxyl. It can only be deprotonated now to -COO- (Negatively charged). The -COO can not accept two protons. Just as the -NH3+ can not accept a 4th proton. This is determined by the atoms' valence and number of electrons
@mrawesome18216 жыл бұрын
@ time 13:15, you wrote glycine as having only one H on the Nitrogen, when it actually has 2 H's. This really confused when you started to count charges...
@ash.toronto314 жыл бұрын
Yeah lol
@Leah4sciMCAT3 жыл бұрын
I’m sorry for the confusion and for the late reply. When neutral and in its de-protonated form, the free amino group of glycine should appear as -NH2. At no point does it actually exist with a single proton. I simply had it appearing that way at the beginning of the problem before I determined if the group was in its protonated (-NH3+) or deprotonated (-NH2) form.
@ryanohara47408 жыл бұрын
You are a tremendous teacher.
@Leah4sciMCAT8 жыл бұрын
thank you
@patrickp45716 жыл бұрын
Clear and simple as always, thank you.
@Leah4sciMCAT5 жыл бұрын
You're very welcome!
@anashchowdhry68798 жыл бұрын
For the last example how does HN got to H3N
@Leah4sciMCAT8 жыл бұрын
at what time?
@skylarmorrison51627 жыл бұрын
Leah4sciMCAT I assume he means at 13:19 when you protonate the amino group
@gabbyc24474 жыл бұрын
Very clear and concise. Thank you so much!
@Leah4sciMCAT4 жыл бұрын
You're very welcome!
@sarajahanara47218 жыл бұрын
Wow you are amazing. I love it!
@Leah4sciMCAT8 жыл бұрын
thank you
@corneliusngandwe2932 жыл бұрын
Very good explaination
@Leah4sciMCAT2 жыл бұрын
Glad you like it!
@tiggertiger94956 жыл бұрын
this helped me on a biochem question, thank you
@Leah4sciMCAT6 жыл бұрын
You're very welcome!
@thecoreybrown5 жыл бұрын
Can someone answer this for me? I thought a molecule that has more H+ ions is BASIC and molecules that don't have that many H+ is acidic? Right or wrong?? for example which is the base and which is the acid of these 2......NaH2PH4 and NaHPO4 and why?
@Leah4sciMCAT5 жыл бұрын
Have you seen my acid/base series? Leah4sci.com/acidbase
@catma4587 жыл бұрын
Thank you.You made it so simple
@Leah4sciMCAT7 жыл бұрын
You're welcome
@tea50204 жыл бұрын
This is such a good explanation thank you!
@Leah4sciMCAT4 жыл бұрын
You're very welcome!
@mohamedelnaas84666 жыл бұрын
U just saved my life,Thank u
@Leah4sciMCAT6 жыл бұрын
Glad I could help!
@JedaJess3 ай бұрын
Thx u so much! ❤
@Leah4sciMCAT2 ай бұрын
you're so welcome!
@AquaticLogic8 жыл бұрын
This is a very good explanation, thank you.
@Leah4sciMCAT8 жыл бұрын
You're very welcome
@mannypotMD8 жыл бұрын
Really helpful. Thank you!
@Leah4sciMCAT8 жыл бұрын
Thank you
@chinedu7128 Жыл бұрын
LET HER COOK!!! wow, you just earned a subsciber!
@Leah4sciMCAT Жыл бұрын
Yay! Thanks so much for watching and subscribing! Glad you liked the video.
@Ruslancho995 жыл бұрын
I love your explanation, it-s simply made and just enough :=)
@Leah4sciMCAT5 жыл бұрын
Glad I could help!
@maatherbasfar90128 жыл бұрын
god bless you for this amazing video
@Leah4sciMCAT8 жыл бұрын
thank you
@user-oz4ur2xl5w Жыл бұрын
Hi, thanks for the video. But why at pH13, amino group did not deprotonate?
@Leah4sciMCAT Жыл бұрын
You're welcome! It did deprotonate. Once it reached the pH of 13, it went from CH3NH3+ to CH3NH2. It lost a proton.
@natan-elmensahsowah45815 жыл бұрын
For pH of 13 for glycine, shouldnt the amino group be deprotonated and not protonated?
@Leah4sciMCAT5 жыл бұрын
at which specific point in the video?
@acepokemontrainer15 жыл бұрын
It is already deprotonated. Instead of H3N+, it has deprotonated at pH 13 to become H2N like she has drawn.
@marissachukwu3065 жыл бұрын
just wanted to clarify, at ph=13, the ph is greater than pka 9.6 of amino group, so amino group should be deprotonated to NH2 from NH3+ right? and thats why you get the charge on the amino group as 0?
@Leah4sciMCAT5 жыл бұрын
At which specific part of the video are we talking about? (timestamp)
@marissachukwu3065 жыл бұрын
@@Leah4sciMCAT at time stamp 15:50
@Leah4sciMCAT5 жыл бұрын
@Marissa Chukwu - correct.
@hmh60404 жыл бұрын
It's so helpful! Thank you!!!
@Leah4sciMCAT4 жыл бұрын
You're very welcome!
@SuperioMan34323 жыл бұрын
omg this makes a ton of sense
@Leah4sciMCAT3 жыл бұрын
So glad it helped you understand!
@dalyam20149 ай бұрын
Shouldn't the amine on GLY be de-porotonated at pH 13 because pH>pKa? To go from neutral NH2 to NH??
@Leah4sciMCAT9 ай бұрын
Yes, the amine will be de-protonated at pH 13. It goes from NH3+ to a neutral NH2. The amine group will never be written as NH (and if it was, it would be negative in charge).
@kierayuan17787 жыл бұрын
very, very helpful! Thank you so much!
@Leah4sciMCAT8 ай бұрын
You're welcome!
@Bettertobeawarriorinagardin3 жыл бұрын
So you said that the neutral form cannot exist, but that the zwitterion is the neutral form and then you claimed that it is the most common form, please elaborate I'm confused
@Leah4sciMCAT3 жыл бұрын
I apologize for the confusion. The amine and carboxyl groups cannot both appear in their neutral form at the same time. In nature, we most commonly find amino acids as a zwitterion where the amine holds a positive charge and the carboxyl hold a negative charge. Overall, these two charges cancel out, creating a net neutral charge for the molecule. The idea is that neither group is neutral by itself, but together they form a net neutral molecule.
@danichang27003 жыл бұрын
THANK YOUUU!! I finally understood what to do if pKa is equal to pH! God bless you (//>^
@Leah4sciMCAT3 жыл бұрын
You're very welcome! I'm so glad to help you understand!
@user-ez8zy2jj4o4 жыл бұрын
great explanation !! thank you ..
@Leah4sciMCAT4 жыл бұрын
You're very welcome
@surat85916 жыл бұрын
Thank you!!! You are a blessing 😍
@Leah4sciMCAT5 жыл бұрын
you're welcome!
@mareimart21274 жыл бұрын
i love this! Thank you very helpful
@Leah4sciMCAT4 жыл бұрын
You're so welcome!
@curiositycatasta5 жыл бұрын
Why is the amino acid Glycine represented with an NH group instead of an NH2 group, and the COOH group as the COO group?
@Leah4sciMCAT5 жыл бұрын
I'm sorry but I don't offer tutoring through KZfaq comments. For help with questions like this and more, I highly recommend joining the MCAT Study Hall. For more details visit join.mcatstudyhall.com/ or contact me through my website leah4sci.com/contact/
@josh63064 жыл бұрын
This was great! Thank you!
@Leah4sciMCAT4 жыл бұрын
You're so welcome!
@stoicsingh4723 жыл бұрын
Omg you are a godsend god bless you
@Leah4sciMCAT3 жыл бұрын
Wow, thanks!
@atousabahrami64174 жыл бұрын
what if you are working with basic amino acid that is already carrying +1 charge?
@Leah4sciMCAT4 жыл бұрын
I'm sorry, but I don't offer tutoring through KZfaq comments. For help with questions like this and more, I recommend joining the MCAT Study Hall. For more details visit join.mcatstudyhall.com/ or contact me through my website leah4sci.com/contact/
@kennedyolson94084 жыл бұрын
Bless you. I understand this well now :)
@Leah4sciMCAT4 жыл бұрын
Awesome!
@nathaniele18357 жыл бұрын
at 12:47, would it be NH2 instead of NH? and O- instead of O? I'm just a bit confused on what the starting molecule of glycine looks like.
@monicabarsoum34345 жыл бұрын
I was confused about this too! idk why she didn't explain this or make a note about it at least:(
@kousalyadevi52095 жыл бұрын
Have the starting material as NH2 and COOH.. Remember NH2 can't be deprotonated further (to NH) and COOH can't be protonated further.
@Leah4sciMCAT3 жыл бұрын
I’m sorry for the confusion and for the late reply. At no point does glycine actually exist with a single proton on the nitrogen or with an uncharged, de-protonated oxygen on the carboxy group. I simply had it appearing that way before I determined if either group was in its protonated or deprotonated form. There really is no “starting molecule” of glycine. It will exist at different charge states, depending on the pH of the surrounding solution. We always have to consider the pH before determining how glycine will appear.
@sammser324 жыл бұрын
I'm confused. Ka is a constant for any given acid, right? So how can it be proportional to the hydrogen concentration? Constants aren't proportional to things! Ahh!
@Leah4sciMCAT4 жыл бұрын
Sorry you're so confused; let's get things cleared up for you. Yes, Ka is a constant for any given acid. Maybe it would be better to say that Ka is proportional to the ratio of [H+]/[HA]. It stands to reason that acids which produce a higher quantity of H+ per unit of acid would have greater Ka values (and thus be more acidic). So even though the Ka doesn’t change for a given acid, it is variable between different acids based on how much H+ that particular acid produces.
@sumayauthmaan48384 жыл бұрын
Just to clarify, does the pH look at the solution, while the pKa looks at the molecule?
@Leah4sciMCAT4 жыл бұрын
I think you’ve got the distinction! The pH looks at the concentration of hydrogen ions in solution, while the pKa is a constant for any given molecule. The pKa gives us information about the acidity of a certain proton on the molecule and whether that proton will dissociate or not at the specified pH.
@monicabarsoum34345 жыл бұрын
i was confident until you did the example with glycine and misdrew it... it got me so confused during the entire example and now I'm just really anxious and confused :( ... please fix this....
@Leah4sciMCAT5 жыл бұрын
at which point of the video are we referring to?
@araza7113 жыл бұрын
You are so great! TY!
@Leah4sciMCAT3 жыл бұрын
You are so welcome!
@manjukumar34064 жыл бұрын
Thankyou very much mam...❤❤💖💖💖
@Leah4sciMCAT4 жыл бұрын
You're welcome!
@kalkidanberhanu77084 жыл бұрын
thanks for a great video!
@Leah4sciMCAT4 жыл бұрын
You're very welcome!
@mianmutahir15657 ай бұрын
THANKU CUTIE
@Leah4sciMCAT7 ай бұрын
You're welcome
@LewisNoname7 жыл бұрын
I really love you, thanks !!!
@Leah4sciMCAT8 ай бұрын
You're welcome!
@cerenavclar14174 жыл бұрын
Thank you so much !
@Leah4sciMCAT4 жыл бұрын
You're very welcome
@tiff678905 жыл бұрын
bless this video
@Leah4sciMCAT5 жыл бұрын
Thanks! Good luck to you :)
@paulmoyo87464 жыл бұрын
Thank you so much
@Leah4sciMCAT4 жыл бұрын
You're welcome!
@liamckinney97174 жыл бұрын
Would you recommend memorizing the pKa values for all amino acids?
@Leah4sciMCAT3 жыл бұрын
Yes and no. Only memorize the estimates I discuss here: leah4sci.com/amino-acid-charge-in-zwitterions-and-isoelectric-point-mcat-tutorial/
@user-ze3bc9yb9y4 жыл бұрын
I have exams in 1hr, wish i saw this much before
@Leah4sciMCAT4 жыл бұрын
Better late than never?
@aderonkeolaoye80526 жыл бұрын
Am confused, at 15:22, when you deprotonate NH2, shouldn't the charge become -1 instead of neutral?
@Leah4sciMCAT6 жыл бұрын
NH2 is -1, but RNH2 is neutral due to having 3 bonds and 1 lone pair
@jeriessilbak71176 жыл бұрын
Thatssss really helpfullll thanks
@Leah4sciMCAT6 жыл бұрын
You're very welcome!
@rufinakore4 жыл бұрын
GOD BLESS YOU
@Leah4sciMCAT4 жыл бұрын
Thank you for that!
@aramebrahimi37543 жыл бұрын
Can't thank you enough!
@Leah4sciMCAT3 жыл бұрын
You're very welcome!
@pkyoupvp4 жыл бұрын
Fantastic
@Leah4sciMCAT4 жыл бұрын
Glad you liked it!
@neilpatel28286 жыл бұрын
Leah, do we need to memorize the pka of the R groups for the Acid Base A Acids for the MCAT? In those the range is +2- -2 correct?
@Leah4sciMCAT6 жыл бұрын
Yes but not 'exact' values. Remember, on the MCAT close enough is good enough.
@tunneltrance6 жыл бұрын
thank you so much
@Leah4sciMCAT6 жыл бұрын
You are welcome!
@dearafaela36724 жыл бұрын
why is carboxylic is charge zero when pH is 1?
@Leah4sciMCAT3 жыл бұрын
Thanks for asking! A pH of 1 is less than the pKa of the free carboxylic acid group (~2.3) on an amino acid. Because of this, the group will appear in its protonated form as -COOH and is neutral in charge.
@brijayejaye54646 жыл бұрын
Great video
@Leah4sciMCAT6 жыл бұрын
Glad you like it!
@thelifeoftoolboxt43596 жыл бұрын
Do you give tutorials about other chapters of Biochemistry?
@Leah4sciMCAT6 жыл бұрын
For the class or MCAT? My biochem resources are specifically designed for the MCAT. For more help with MCAT biochem, I recommend joining the MCAT study hall. Full details: join.mcatstudyhall.com/
@gandhimanikandan24908 жыл бұрын
at ph 13 why did the amine group get protanated ... is should be deprotonated ryt ? bcoz the surrounding has got less H+ ion they y did the NH was protonated ....im confused ..
@Leah4sciMCAT8 жыл бұрын
+gandhi manikandan what point in the video?
@gandhimanikandan24908 жыл бұрын
+Leah4sciMCAT mam will the ammino acids we take in food are always in zwitter form ie amine is NH3 + and carboxyl group is coo - ??
@gandhimanikandan24908 жыл бұрын
+Leah4sciMCAT just nw watched ur vid again ..nw its clear just pls clarify the doubt above ...ie protein we eat has their ammino acids in zwitter form ? is it ?
@pfunzonevhusenga86025 жыл бұрын
Brilliant
@Leah4sciMCAT5 жыл бұрын
Thanks!
@pfunzonevhusenga86025 жыл бұрын
You're welcome. I nailed the test😃😃😃.
@Leah4sciMCAT5 жыл бұрын
That's amazing! So glad to hear it :)
@kovalchuk718 жыл бұрын
Why do you have the Amine Group as "H2N" at the beginning of the video, but as "HN" at the end of the video?
@Leah4sciMCAT8 жыл бұрын
Not sure I understand where you're seeing HN
@anashchowdhry68798 жыл бұрын
on the amino group for the last exmaple
@acepokemontrainer15 жыл бұрын
She drew H(space)N so that she eventually fills in all the numbers as she showed the specific pH values. Depending on the pH, the amino group is protonated or deprotonated, and she shows that with her drawings.
@negarolfati362 жыл бұрын
Excellent job Leah, thanks a lot! Just one question, regarding the quiz on your website: In part 3, we are asked to find the charge of Cys at PH = 4. Pka values for Cys are as follows: (Pka(COOH):1,71, Pka (NH2): 10,78, Pka(R): 8,33 ). The solution suggests change 0 for the side chain. Could you please explain this to me? I would expect to see +1 for the side chain and not zero, as PH is much less than the Pka for side chain, which means that the side chain should get protonated (conveting to S2H+ from SH). Am I missing something? All help would be appreciated.
@Leah4sciMCAT2 жыл бұрын
You're very welcome! Since I don't offer tutoring over social media, I would first suggest you use the download link at the bottom of the practice quiz to access the PDF quiz solutions. If you would like a more detailed explanation, I recommend joining the MCAT Study Hall. For more details visit join.mcatstudyhall.com/ or contact me through my website leah4sci.com/contact/
@elmerit28484 жыл бұрын
It's not log, it's lg.
@Leah4sciMCAT4 жыл бұрын
In the Henderson-Hasselbalch equation, we use a logarithm with a base of 10 which is abbreviated “log”.
@zarakristen29673 жыл бұрын
Commonly used as log
@ghassanauf81033 жыл бұрын
I don’t know but why you are so concerned about acetic acid !!! Where is the amino acid in this whole lecture!!!!
@Leah4sciMCAT3 жыл бұрын
An amino acid is an organic compound that contains both amine and carboxylic acid functional groups. In this video, I first look at acetic acid and methylammonium, as examples of how those same functional groups would behave on their own at various pH values. Then, to apply that knowledge, I turn to the example of the amino acid glycine at 12:37 to explain how these functional groups would function together within the same molecule at various pH values.