I am investigating peptide hydrolysis, and I have read that sulfuric acid, although a diprotic acid, does not use its second acidity when hydrolysing peptide bonds. Why is this?
Acid hydrolysis is a catalytic process, where H+ is not consumed. The peptide does not know, where the H+ comes from. It may even come from water.
Thanks Jukka Salminen . I have read that acid hydrolysis is catalytic in nature, however other sources state that sulfuric acid is 'consumed' as it neutralises the amino groups. For example, if starting with a 6 M solution of sulfuric acid, and adding protein (assuming no change in volume), will I still have a 6 M solution after hydrolysis?
We are talking about three different processes: Hydrolysis, protonation of amino groups and dissociation of carboxylic acids (amino acids). The composition and pH of the final solution depends on relative amounts of different anions. Sulphate does not disappear but you get free amino acids that have both carboxylic acid and amino groups that all contribute to the final hydrogen ion activity. Bisulphate has pKa ~2 so it can be considered a strong acid that is fully dissociated.
- Badges
- Science topic
- Similar topics
- Econ
- Manufacturing
- Industry