Web Results


The isoelectric point (pI, pH(I), IEP), is the pH at which a particular molecule carries no net electrical charge or is electrically neutral in the statistical mean.The standard nomenclature to represent the isoelectric point is pH(I), although pI is also commonly seen, and is used in this article for brevity. The net charge on the molecule is affected by pH of its surrounding environment and ...


0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 pH 0.0 0.5 1.0 Mole fraction H 3N + H OH O 3N O O H 2N O O pK a 2.3 a 9.7- Isoelectric Point of a Neutral Amino Acid - Alanine + pI ...


The isoelectric point of an amino acid is the pH at which the amino acid has a neutral charge. You will learn how to calculate the isoelectric point, and the effects of pH on the amino acid's overall charge. We will also discuss zwitterions, or the forms of amino acids that dominate at the isoelectric point. By Tracy Kovach.


What is an isoelectric point? The word isoelectric or isoelectronic comes from ‘iso,’ which means the same, and ‘electric,’ which implies charge. The isoelectric point or pI of an amino acid is the pH at which an amino acid has a net charge of zero.


The isoelectric point or isoelectric pH (pI) of a molecule is the pH at which the molecule carries no net charge. Amino acids exist as ampholytes (zwitterions) because of their polar groups. So they are either cationic or anionic in acidic or al...


ISOELECTRIC POINTS. ... alanine has a protonated (and thus uncharged) carboxyl group and a positively charged amino group that is also protonated. Under these conditions, the alanine has a net positive charge of 1. As base is added, the carboxyl group loses its proton to become a negatively charged carboxylate group, and the pH of the solution ...


The isoelectric point, pI, is the pH of an aqueous solution of an amino acid (or peptide) at which the molecules on average have no net charge. In other words, the positively charged groups are exactly balanced by the negatively charged groups. For simple amino acids such as alanine, the pI is an average of the pK a 's of the carboxyl (2.34 ...


Alanine L-Alanine is a neutral, genetically coded amino acid. Symbol ala a Molecular formula C 3 H 7 NO 2 Molecular weight 89.09 Isoelectric point (pH) 6.00 pK a values 2.35, 9.87 CAS Registry Number 56-41-7 3D Molecular Model. If you have installed MIME types for Chemistry for use with the Alchemy mol format, you may click at the 3D model above.


Table of pK a and pI values. The pK a values and the isoelectronic point, pI, are given below for the 20 α-amino acids. pKa 1 = α-carboxyl group, pK a 2 = α-ammonium ion, and pK a 3 = side chain group.


pK and pl Values of Amino Acids. Name. pK. pI. at 25°C. pK. α-CO2H. pK. NH3. pK. R-group. Alanine. 2.35. 9.87 . 6.11. Arginine. 2.18