Acid-Base Properties of Amino Acids

Acid-Base Properties of Amino Acids Investigate the pH-dependent protonation of amino acids. Tasks Create and optimize a glycine molecule (). Open Build Menu and select Add Hydrogens for pH... Choose different values of pH : 1,2,3,…,13 and note the effect of pH shift on electrical charge of glycine. In a new View, create a (Glutamic acid - Lysine) dipeptide using Build Menu > Insert > Peptides... Set pH to 3 and calculate the correspondent electrical charge of the dipeptide. Do the same for pH=7 and 13. When performing a paper electrophoresis at these pHs, in which direction will the dipeptide move (anode or cathode) ? Solution Glycine electrical charge according to pH shift: pH<5: ; net charge =+1 5≤pH<10: ; net charge =0 10≤pH≤13: ; net charge =-1 Glu-Lys dipeptide: Further readings Categories: Teaching Updated: December 01, 2009 Share on Twitter Facebook Google+ Reddit

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