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Amino acids

Amino acids

by Shashank Todwal -
Number of replies: 6

Why are (alpha)-amino acids neutral.Books say that it is because it has basic(NH2) as well as acidic group(-COOH).

I think it should be termed as acid as well as basic because definition of acid(/basic) just says acceptance(/donation) of electrons which are both satisfied simultaneously by them.

In reply to Shashank Todwal

Re: Amino acids

by Chandni Bhatia -
I think amino acids are amphotric .When zwitter ion is formed the acid contains positive as well as negative charge and if  the magnitude of charges are equal then the  acid is neutral
In reply to Shashank Todwal

Re: Amino acids

by amit kumar -
an acid or a base, is dependant on the solvent.

in normal circumstances we take water, and when an amino acid is dissolved in water, then the zwitter ion is formed which takes up the OH- and the H+. thus producing no acidity or basicity in the solution. thus they are regarded as neutral.
In reply to amit kumar

Re: Amino acids

by Shashank Todwal -

Dear Amit and Chandni,

With whom does any base react.Obviously with an acid.Suppose I add base,won't it react with amino acids.If yes then they are acids.

With whom does any acid react.Obviously with an base.Suppose I add acid,won't it react with amino acids.If yes then they are base.

Thus amino acids on these arguments must be termed an acid as well as base and not neutral.

Plz reply.

In reply to Shashank Todwal

Re: Amino acids

by Manoj Tirukodi Radhakrishn -

Hello hero what chandni said is 100% correct but the girl should not have said that to be amphiprotic or amphoteric.This zwitter ion formation is an intermolecular phenomenon.

If your intrest is to know why these amino acids are neutral, its due to zwitter ion formation.Basically the presence of a donor site and an acceptor site in the same molecule leads to this phenomenon.

As soon as the solution of amino acid is prepared the e- pair transfer takes place from 1end of 1-atom to another.

So wher's the need for further protonation.

Hence these are Neutral as now there is neitheir a proton acceptor nor a proton donor.

If you want me to explain , first ask a question why a base reacts with an acid. The answer is obviously due to the presence of a proton donor and a proton acceptor or due to the the presence of an electron rich compound and an electrn deficient compound.

Now ask the qtn why an acid reacts with a base

The answer is obiously the same one.

So if ther's niether a H+ acceptor nor a H+ donor why would there be rxn with some acid or base

Actually Mr.Todwal What i spoke is a bit wrong as there are some exceptions but you may manage as whatever i have spoken is what is written in books.

In reply to Shashank Todwal

Re: Amino acids

by Chandni Bhatia -
For information on amino acids read NCERT text book.Answer to your question is given there. 
In reply to Chandni Bhatia

Re: Amino acids

by Manoj Tirukodi Radhakrishn -

So what do you want to say chandni, You seem to be saying that m ans is wrong.I litrally hate NCERT so i did not buy em

Any ways can you please present what the fellow has published