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What are ions of molecules interacting with in vivo

  1. Nov 28, 2011 #1
    For example:

    amino acids that are floating around, some with charge at physiological pH. My question is what exactly do the charged amino acids form a salt with? other amino acids? sugars? fatty acids? whatever happens to have an opposite charge and is close?

    A rephrasing: I am thinking about how how in o chem acid base reactions we added sodium hydroxide to a solution of benzoic acid to create the conjugate base of benzoic acid. In the case the benzoic acid forms a salt with the sodium, so what do the amino acids form salts with in vivo?
  2. jcsd
  3. Nov 28, 2011 #2


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    Most salts in solution exist as separated ions. If you dissolve table salt in water, you have Na+ ions and Cl- ions in solution, which are not stably associated with each other. In the same way, most of the ions inside the cell are not stably associated with counter ions.

    There are, of course, exceptions to this rule. For example, Mg2+ fairly stably associates with nucleotide triphosphates like ATP, and various proteins or other biomolecules often have specific charged sites that will stably bind ions from solution.
  4. Nov 29, 2011 #3
    Do they need to? Equilibrium conditions favour the ionic forms of ions like potassium and the various amino acids in the cytosol.
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