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THE KINETICS OF THE REACTION WHICH TAKES PLACE BETWEEN IODOACETIC ACID AND GLYCINE
1Division of Biochemistry, University of California Medical School, Berkeley.
The Journal of General Physiology
|October 30, 2009
Summary
The reaction between glycine and iodoacetic acid occurs in two steps, with only the glycine anion participating. This ionic reaction exhibits salt catalysis, influenced by primary and secondary salt effects.
Area of Science:
- Biochemistry
- Chemical Kinetics
Background:
- Glycine, an amino acid, plays a crucial role in biological systems.
- Understanding the reaction kinetics of amino acids with alkylating agents is important for biochemical studies.
Purpose of the Study:
- To investigate the reaction kinetics between glycine and iodoacetic acid.
- To elucidate the mechanism and factors influencing this reaction.
Main Methods:
- Polarographic method was employed to study the reaction kinetics.
- Kinetic equations were utilized to analyze the reaction mechanism.
Main Results:
- The reaction proceeds in two consecutive steps, with a velocity constant ratio of 2:1.
- Only the anionic form of glycine reacts, with reaction rates proportional to glycine anion concentration.
- The reaction is ionic, demonstrating positive salt catalysis involving primary and secondary salt effects.
Conclusions:
- The reaction mechanism involves the sequential replacement of glycine's amino group hydrogens by acetyl radicals.
- The reactivity is specific to the glycine anion due to the available electron pair on the nitrogen atom.
- The findings support Brönsted's hypothesis on salt effects in ionic reactions.
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