Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1985-9-3
pubmed:abstractText
Using 31P NMR spectroscopy, we have measured the rate of ATP synthesis, and the free concentrations of ATP, ADP, cytoplasmic Pi, and H+ in maize root tips under a wide range of conditions. We show that the ratio [ATP]/[ADP] in normoxic root tips is greater than 25. We found no simple relationship between the concentration of ATP and the rate of ATP synthesis: when the rate of ATP synthesis decreases in response to different treatments, the concentration of ATP can increase, decrease, or remain unchanged. Clear relationships were obtained, however, when the rate of synthesis of ATP was plotted against the logarithm of the ratio psi, defined as [ATP]/[ADP][Pi][H+]. Two curves were obtained, depending on which of two situations pertained. First, if mitochondrial ATP synthesis was inhibited, e.g., by KCN or hypoxia, ln psi decreased monotonically as rates of ATP synthesis decreased. The decrease in ln psi may account for decreases in the rates of biosynthetic reactions dependent on ATP, such as protein synthesis, as they approach equilibrium. Second, if consumption of ATP for biosynthetic reactions was inhibited, by treatment with succinate, ln psi increased as rates of ATP synthesis decreased. The increase in ln psi may account for decreases in the rate of ATP synthesis, as oxidative phosphorylation approaches equilibrium.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
240
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
712-22
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Relationships between the rate of synthesis of ATP and the concentrations of reactants and products of ATP hydrolysis in maize root tips, determined by 31P nuclear magnetic resonance.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.