The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

what differentiates polar and non polar amino acids?

what differentiates polar and non polar amino acids?
Hi there,

While you're waiting for an answer, did you know we have 300,000 study resources that could answer your question in TSR's Learn together section?

We have everything from Teacher Marked Essays to Mindmaps and Quizzes to help you with your work. Take a look around.

If you're stuck on how to get started, try creating some resources. It's free to do and can help breakdown tough topics into manageable chunks. Get creating now.

Thanks!

Not sure what all of this is about? Head here to find out more.
Reply 2
Avatar for Dan12
Dan12
It will be the side chain (a.k.a. the R group) of the amino acid. If the side chain is positively or negatively charged, amino acid is polar. If side chain is neutral, amino acid is non-polar. I think that is it.
Original post by HaveFaith
what differentiates polar and non polar amino acids?


The amino and carboxyl groups do not play a role in determining polarity. Polarity, and some other properties are determined by nature of side chain. A methyl side chain, f.i., would be non-polar; that is why alanine is non-polar. A hydroxyl group as side chain would be polar; that is why serine and threonine (in our example) are polar. Polarity is defined by a difference in the attraction for an electron, which you wouldn't expect with simple Carbon compounds, but which would be predicted for Oxygen etc molecules.
Reply 4
Avatar for Physical
Physical
1
Original post by HaveFaith
what differentiates polar and non polar amino acids?


Do you know what polar means, in terms of chemistry? If not, then you'll be best learning what it means, then by default you should be able to look at an amino acids' side chain, aka, R-group, to determine whether it's polar or non-polar.

In simple terms, and with regards to amino acids, polarity results from two atoms sharing their bonding electrons unequally. The resulting bond is 'polarised' in one direction (toward one of the atoms), depending on the electronegativity of the atoms (but in the case of a alkyl group, the geometry of the bonds around the central carbon atoms cancel the polarising effect and result in a non-polar species).

For example, in an oxygen-hydrogen bond, the oxygen atom attracts the bonding electrons more strongly than the hydrogen atom, so the electrons density lies more around the oxygen atom; which means the negative charge lies more on the oxygen atom. Incidentally, the hydrogen atom has less electron density around it, or less negative charge.

What results from the above situation is the oxygen atom having slight negative charge associated with it, and the hydrogen a slight positive charge (because the positive nucleus is less shielded by the negative electrons that are spending more time hanging out with oxygen..).

Polarity is normally is represented by lower case greek letter, delta, and is distinct from being ionic, or holding a full + or - charge.

In terms of biochemistry, where water is the solvent that live thrives in, polarity is really important.

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you