Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1981-9-15
pubmed:abstractText
Experiments with respiration deficient (rho-), ADP/ATP transport deficient (op1) and double (op1 rho-) mutants, with glycolytic and tricarboxylic acid cycle substrates showed that the substrate-induced acidification of yeast suspensions is closely associated with glycolysis. The glucose/proton stoichiometry is 2.5 : 1 to 4 : 1 depending on glucose concentration. The kinetics of the process are complex, the acidification curve having a very fast initial component and two slower exponential components. The first component suggests an initial proton efflux from endogenous sources, triggered by exogenous substrates. The acidification process exhibits two Km values at about 1 and 15 mM D-glucose, indicating two distinct saturable pathways of proton extrusion. The total extent of acidification and thus the final pHout reaches a saturation value with increasing glucose concentration and suspension density. Both the total extent and the rate of acidification are subject to control by extracellular pH which reflects the tendency of the cells to build a fixed [H+]out/[H+]in ratio. When the control is lifted, both quantities are considerably increased. A crucial role in the substrate-induced acidification is thus played by active membrane processes and their control mechanisms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
643
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
572-82
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Factors governing substrate-induced generation and extrusion of protons in the yeast Saccharomyces cerevisiae.
pubmed:publicationType
Journal Article