Relation between pH and pKa of amino acids - A Quick Review

Hi guys, in this video I have tried to explain the relation between pH and pKa in connection with amino acids. If you have any questions feel free to ask in the comment section below. Under physiological Ph primary amino group undergo protonation and primary carboxylate group undergo deprotonation.

[@mellisaalvarez4859]

HA! I really did learn more in 6 minutes than I did in my chemistry classes! Thank you :)

[@jonqn07]

Thank you VERY MUCH Dr. Mungli! Your video is so clear and super helpful. This is exactly what I am looking for. God Bless!

[@DrMungli]

+J Bond : thank you, I'm glad my video helped you to understand this concept well. Best wishes

[@dtanoli]

Best Explanation on a beautiful sunny Morning.Thanks

[@DrMungli]

Thank you Dr Nasser. I'm glad you like the video.

[@hanieg2236]

Thank you so much Dr! It was a great AHA moment in my mind when I understood the concept!

[@matteosaveri641]

So, hypothetically if we have a pH < 2, both groups will be in the protonated form?
And if we have a pH > 9.5, both groups will be deprotonated?
Is this the reason why aminoacids are buffers?
Thank you very much Dr. Mungli for your CLEAR explanation. Greetings from Italy!

[@DrMungli]

You got it right. That's true. I'm glad that you have found this video useful. Best wishes.

[@irinakhokhryakova6825]

Great explanation! Thank you very much!

[@DrMungli]

Thank you Irina

[@elizabathalungal5783]

Thanku for yr explanation sir, kindly repeat if ph is more than pka what will happen to the person and what must do to be normal value both of them?

[@aleishaobrien5394]

This was really well explained! Thank you so much. You tied all the concepts I was stuck on in together

[@YourManasi]

Wow Sir,,,,you made it crystal clear....a big thanks🙏🙇....

[@niiaa17]

You explain this so well! Bravo.

[@DrMungli]

Thank you. Consider SUBSCRIBING to the channel for regular updates.

[@NoticeMeSenpaiii]

Thank you!!! I'm in my first week of BioChem, and I was already confused. This was very clear. Do protonation and deprotonation occur when the pH is very close to the pKa, or only when there is a significant difference between the 2?

[@DrMungli]

You are most welcome. Protonation and deprotonation is significant as the pH goes away from pKa. Please watch the video again to make the concept clear.

[@saumyarai7386]

Very nicely explained!

[@jeevidhabalasubramaniam2341]

Awesome video sir... keep going..

[@DrMungli]

Thank you, I will

[@promisemethis1035]

Studying for the mcat and this helped so much!! Thank you

[@DrMungli]

UR most welcome. I'm glad this video has been helpful to you while you prepare for MCAT.

[@amitarao_19892]

999 likes the phle but 1like from my side 🥳😁.........and complete 1k __________🤞🤞 such a big happiness 😊😊

[@twinkle1548]

Very well explanation

[@renaudhendrik]

Awesome! Thank you Dr. Mungli!!!! :D

[@DrMungli]

Thank you and best wishes to you.

[@mishaalshariff6893]

Very, very helpful! Thank you for sharing this great explanation :)

[@sumanghosh5353]

its really helpfull sir

[@maryamginem6854]

You made a complicated concept so easy!

[@irisforgiarinipasini1753]

very good. Thank you

[@harshit155]

Thank you Sir. You made it more than easy.

[@cassandrasantos2559]

this was very helpful, thank you!!

[@DrMungli]

You are most welcome

[@leticiamatsubara7298]

Thank you sir!!!

[@LadyBernkastel92]

Thank you so much, this is laid out very helpfully!

[@TheOriginalArchivist]

Great video. Thanks for the help.

[@emeralds3392]

Simple and comprehensive 😍 thank you

[@naeemshaikh4055]

thnk u so much sir..and i want to ask u about my practical..Aim of practical is Preparation of buferrs of various pH & determine the pKa of a buffer system..specially about Phosphate buffer?

[@derekanderson8659]

Great explanation. Thank you!

[@jashangirdhar1093]

Hello Sr there is one doubt that when the ph=pka the drug will be 50%ionised and 50% unionised is it correct???? It also means that drug should follow hlb scale i.e hydrophilliic lipophillic scale it means that drug should be highly soluble and absorbed though lipid membrane

[@dv_wild]

At PH value greater than pKa of COOH group in the amino acid, the amino acid will be having what charge?

[@BhavyaKansal18]

Thankyou for the explanation.
I had a doubt with pI vs pH as well.. harper says that at pH= 7, a molecule with pI = 6 will have a net positive charge. How is that possible?
Because if we treat pI as pK of dominant (acidic/basic) group of the amino acid, then according to that, pK

[@raghavakrishna3583]

sir, please justify the statement 'lower the pka of an acidic compound stronger the acid i.e. great extent of ionization takes place and less amount of unionized form(pka).' if correct. please explain..........

[@DrMungli]

You are right. In acid pH specially when Ph is much lower than pka, molecule will be predominantly protonated (ionized) and less will be in unionized form.

[@sumathijayaraman3415]

Sir can you tell clinical importance of protection &deprotenation ?

[@alissakan4992]

Am a beginner catching up in studying biochemistry courses.... just wanna ask a question... tho it may sound lame
why do we have to balance the content of H+ ions between the amino acid and the solution? Thank you in advance for solving my Q

[@mahimakawa1234]

Sir, can we say pKa is a type of pH? And why does this relation between pH and pKa results in tranfer of H+ ? Please explain, i am confused. Thank you. 😊

[@oluwatomioredein]

I would also like this explained

[@WaldoNevada]

Thank you so much!

[@betbet1503]

Thank you! So helpful

[@DrMungli]

+Bethany Fields :Thank you. I'm glad this video helped you.

[@inklisanpatel8847]

All videos e helpful

[@DrMungli]

You are most welcome.

[@ibhadeerua1993]

You are amazing, thank you so much 😁

[@DrMungli]

You're welcome 😊

[@SamSenoSurigao]

Thank you Dr. Mungli!!!!

[@DrMungli]

+Samantha Surigao: your very welcome

[@mohammadiqbal1067]

Great

[@jodyjoecropprue9674]

Thank you very much for helping me in this.

[@DrMungli]

+Jodyjoe Cropprue : you are most welcome

[@Stomyphotography]

Thank you.

[@kkm5384]

thank you.
though i need some clarification.
You are comparing both materials i.e. here blood and amino acid, and say that COOH undergo deprotonation and NH2 undergo protonation. is this happen when these two materials are mixed? (tried to listen 2-3 times) but did i miss that point of mixing these two?

[@princessfizzarizvi]

ur video is really helpful👍sir plz explain the following ques

[@DrMungli]

+princessfizzarizvi : thank you, I'm glad this video has helped you.

[@harshadanatekar688]

Very helpful! Thank you sir

[@DrMungli]

+Harshada Natekar Thank You. I'm glad you found the video useful.

[@RahulYadav-mg5hn]

Thankyou sir

[@tanmaybehera9745]

Sir how can we decide the net charge of a peptide chain.(say Aspartate- Alanine-Serine-Valine-arginine )at physiological pH? How do we proceed for that!!

[@DrMungli]

One need to calculate the protonation and deprotonation of the peptide chain at that specific pH.

[@princessfizzarizvi]

how will the carboxylate gp of aspartate function at physiological pH as a nucleophile or electophile and as a conjugate acid or base

[@jahangirjahangir6919]

can u plz tell me that pka of COOH is 2 and pka of NH2 is 9.5?means these are fixed values?haina??

[@anaculver2303]

so helpful!

[@DrMungli]

Thank you Ana, Im glad my video explanation helped you.

[@fairzax7531]

I have a question. I dont understand the concept of 50% of COO- and another 50% of COOH. what does it mean?

[@DrMungli]

Means out of 100 amino acids, 50% of their carboxylic groups are in COO- and 50% as COOH

[@TheGlee4Me]

Thank you this helped a lot!

[@DrMungli]

+Anh Vo Thank You. I'm glad you found the video useful.

[@gauravresearch8]

Very nice but basic concepts are not explained. Would have been much better with basic information

[@DrMungli]

Noted

[@charlotteignatova1849]

Thank you so much for the great video! During my chemistry test I will be given only an amino acid and a pH value. Is it possible to know how to draw the structure of the amino acid in different pH values without being given a pKa?

[@DrMungli]

Yes it is possible only if you have memorized Pka values for primary amino group, primary carboxyl group and the side chain.

[@samuelbonne4047]

You should come teach us at MIT

[@philosopherkinggaming_6980]

So, from what I understand, the pH of the solution determines whether or not the carboxyl and amine group of the amino acid are protonated. If the pH of the solution is higher than the pKa of the group, the solution is more BASIC than the group in question, causing deprotonation of the functional group. In the same line, if the pH is lower than the pKa of the functional group then the solution is more ACIDIC than the functional group, protonating it. Is that right?

[@DrMungli]

That's right.

[@DrMungli]

@Jonathan Palman: I would say yes.

[@habesha4642]

What about the ionization constants

[@kerlysaturn1984]

wow i was really about to click off...thank you..God Bless!! *prayer hands*

[@DrMungli]

You are so welcome

[@emanfathy888]

Hey, dr.Prakash ,, I am Eman from Egypt ,,,could you please illustrate what PH means , how it affects on the whole protein charge , and the same to PKa ? is thereva relation between Zwitter ion an equilibrium between PH and PKa?
Thanks in advance.

[@DrMungli]

+Eman Fathy : Yes change in pH will change the ionization status of a protein. Change in the ionization status would lead to change in the overall charge of a protein. This lead to change in how a protein interact with other protein. Yes there is a relation between zwitterion equilibrium and pH and pKa.

[@shahbaz9231]

lower Pka = Strong Acid

[@anuupamkumar9405]

thank you very sir was really helpful.........

[@DrMungli]

+anuupam kumar Thank You. I'm glad you found the video useful.

[@Envirodrishti]

Define pH and pK

[@Editsmohit]

PH is potential of hydrogen
Pka is dissociation constant of acid
And pkb is dissociation consatant of base

[@gfkenya9926]

Many people owe their medical degrees to you!