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Do the pH and other ions affect the hydrolysis of ATP
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Aaron Turpen
Do the pH and other ions affect the hydrolysis of ATP
OK. Let’s answer the questions you pose:
How does the pH affect the hydrolysis of ATP?
High concentrations of hydrogen ions or hydroxyl ions (“extremes of pH” — as you quote) cause acid or alkaline hydrolysis. The mechanism of alkaline hydrolysis is presumably through a cyclic intermediate, as with the hydrolysis of RNA. Acid hydrolysis of ATP requires very low pH — for example it has been studied in 3M perchloric acid — and the mechanism is quite complex, according to work published by Hutchings et. al. in 1981.
Why is it even relevant if the solution is buffered or not?
In unbuffered solutions the pH may easily deviate from the physiological range. This is a practical consideration of work in vitro. Physiological and cellular systems are highly buffered by a variety of ions and even macromolecules so the problem does not arise.
Are there other effects that influence stability in animal cells?
You are mistaken in your assumption that there is a particular need to prevent hydrolysis of ATP within animal cells. This appears to be based on a misunderstanding of a Wikipedia entry which is more concerned with the chemistry of ATP rather than its situation in the cell.
High concentrations of hydrogen ions or hydroxyl ions (“extremes of pH” — as you quote) cause acid or alkaline hydrolysis. The mechanism of alkaline hydrolysis is presumably through a cyclic intermediate, as with the hydrolysis of RNA. Acid hydrolysis of ATP requires very low pH — for example it has been studied in 3M perchloric acid — and the mechanism is quite complex, according to work published by Hutchings et. al. in 1981.
Why is it even relevant if the solution is buffered or not?
In unbuffered solutions the pH may easily deviate from the physiological range. This is a practical consideration of work in vitro. Physiological and cellular systems are highly buffered by a variety of ions and even macromolecules so the problem does not arise.
Are there other effects that influence stability in animal cells?
You are mistaken in your assumption that there is a particular need to prevent hydrolysis of ATP within animal cells. This appears to be based on a misunderstanding of a Wikipedia entry which is more concerned with the chemistry of ATP rather than its situation in the cell.
@TomD — ATP is an important metabolite, and its generation and the coupling of its hydrolysis to chemical, electrochemical and mechanical processes is important. Whether it is “the basis of life” any more than DNA, RNA, proteins, lipids, NAD etc. is an irrelevant and fruitless question. What I maintain is that the problems Nature had to solve with respect to ATP were those already mentioned. Its activation energy and chemistry are such that there is no tendency for its spontaneous hydrolysis at physiological pH, so preventing this is not a problem and certainly not the “the basis of life”.More
OK. Let’s answer the questions you pose:
How does the pH affect the hydrolysis of ATP?
High concentrations of hydrogen ions or hydroxyl ions (“extremes of pH” — as you quote) cause acid or alkaline hydrolysis. The mechanism of alkaline hydrolysis is presumably through a cyclic intermediate, as with the hydrolysis of RNA. Acid hydrolysis of ATP requires very low pH — for example it has been studied in 3M perchloric acid — and the mechanism is quite complex, according to work published by Hutchings et. al. in 1981.
Why is it even relevant if the solution is buffered or not?
In unbuffered solutions the pH may easily deviate from the physiological range. This is a practical consideration of work in vitro. Physiological and cellular systems are highly buffered by a variety of ions and even macromolecules so the problem does not arise.
Are there other effects that influence stability in animal cells?
You are mistaken in your assumption that there is a particular need to prevent hydrolysis of ATP within animal cells. This appears to be based on a misunderstanding of a Wikipedia entry which is more concerned with the chemistry of ATP rather than its situation in the cell.
OK. Let’s answer the questions you pose:
How does the pH affect the hydrolysis of ATP?
High concentrations of hydrogen ions or hydroxyl ions (“extremes of pH” — as you quote) cause acid or alkaline hydrolysis. The mechanism of alkaline hydrolysis is presumably through a cyclic intermediate, as with the hydrolysis of RNA. Acid hydrolysis of ATP requires very low pH — for example it has been studied in 3M perchloric acid — and the mechanism is quite complex, according to work published by Hutchings et. al. in 1981.
Why is it even relevant if the solution is buffered or not?
In unbuffered solutions the pH may easily deviate from the physiological range. This is a practical consideration of work in vitro. Physiological and cellular systems are highly buffered by a variety of ions and even macromolecules so the problem does not arise.
Are there other effects that influence stability in animal cells?
You are mistaken in your assumption that there is a particular need to prevent hydrolysis of ATP within animal cells. This appears to be based on a misunderstanding of a Wikipedia entry which is more concerned with the chemistry of ATP rather than its situation in the cell.
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