Comments on: Tequila time! http://www.sciencebase.com/science-blog/tequila-time.html Science Blog from Freelance Science Writer David Bradley Thu, 09 Feb 2012 08:25:37 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: sciencebase http://www.sciencebase.com/science-blog/tequila-time.html/comment-page-1#comment-1357 sciencebase Tue, 13 Jun 2006 19:24:01 +0000 http://www.sciencebase.com/science-blog/tequila-time.html#comment-1357 I was initially at a loss as to what pI values were. Obviously, we have pH and pKa, and logP and logP(i) etc etc...but then I thought maybe the I (el) is an l (eye) and it struck me... "Isoelectric point" By definition (courtesy of Wikipedia, of course), <a href="http://en.wikipedia.org/wiki/Isoelectric_point" rel="nofollow" rel="nofollow">Isoelectric point</a> is the pH at which a molecule carries no net electrical charge and is a rather useful value for those studying amino acids and drug molecules, for instance. Amino acids feature in pI discussions primarily because they have an acid (carboxyl group) and a base (amino group) component and so are amphoteric. Anyway, I'll leave readers to take in the Wikipedia entry on the subject and if pI ever features in a news story, I'll be sure to give this comment a mention. I was initially at a loss as to what pI values were. Obviously, we have pH and pKa, and logP and logP(i) etc etc…but then I thought maybe the I (el) is an l (eye) and it struck me…

“Isoelectric point”

By definition (courtesy of Wikipedia, of course), Isoelectric point is the pH at which a molecule carries no net electrical charge and is a rather useful value for those studying amino acids and drug molecules, for instance. Amino acids feature in pI discussions primarily because they have an acid (carboxyl group) and a base (amino group) component and so are amphoteric.

Anyway, I’ll leave readers to take in the Wikipedia entry on the subject and if pI ever features in a news story, I’ll be sure to give this comment a mention.

]]> By: Hannah http://www.sciencebase.com/science-blog/tequila-time.html/comment-page-1#comment-1352 Hannah Tue, 13 Jun 2006 18:17:22 +0000 http://www.sciencebase.com/science-blog/tequila-time.html#comment-1352 hi...was wondering if you could add some stuff about pI values onto your chemistry tutorials...would really help! hi…was wondering if you could add some stuff about pI values onto your chemistry tutorials…would really help!

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