Polarity of Amino Acids Question

[billnye0605]

Hello. I am a student working on a research project. I have been searching for the specific polarity of arginine, an amino acid. I was hoping to find a specific number for the polarity, but I could not find anything. Does anyone know 1- where I can find this number? 2- How I can obtain this number? 3- If anyone knows this number, can I have it?

Thanks!

[CaptainPanic]

I'm not sure how to answer this because I have not often encountered a number for polarity. Which units does polarity have, accoring to you?

 

I've heard (merely a rumor) that there is some kind of UV-shift scale where a chemical compound changes color depending on the polarity of the solvent in which it's dissolved.

Iodine is an example, it changes color depending on the polarity of the solvent in which you dissolve it. but whether you can use that for determining the polarity of arginine, I don't know. Arginine is not a solvent (it's not even a liquid when it's pure).

 

Another scale (again a rumor) is simply a comparison between two compounds: one is, I believe hexane, the other I forgot.

 

I called all these rumors because I failed to find any info to back up my claims here. But perhaps this helps others to add some real facts here

 

p.s. the polarity of arginine changes with pH: at certain pH values it is positively or negatively charged. And I wouldn't be surprised if some funny stuff happens with the electron positions as a function of pH in the neutral range (zwitterion). Therefore I doubt that you can find 1 single number for the polarity of Arginine.