The potential effect of low cell osmolarity on cell function through decreased concentration of enzyme substrates

Raven, JA

The potential effect of low cell osmolarity on cell function through decreased concentration of enzyme substrates

Raven, JA

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Publication Type:: Journal Article
Citation:: Journal of Experimental Botany, 2018, 69 (20), pp. 4667 - 4673
Issue Date:: 2018-01-01

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Field	Value	Language
dc.contributor.author	Raven, JA https://orcid.org/0000-0002-2789-3297	en_US
dc.date.available	2018-07-03	en_US
dc.date.issued	2018-01-01	en_US
dc.identifier.citation	Journal of Experimental Botany, 2018, 69 (20), pp. 4667 - 4673	en_US
dc.identifier.issn	0022-0957	en_US
dc.identifier.uri	http://hdl.handle.net/10453/131089
dc.description.abstract	© The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. Some freshwater algae have lower (<130 osmol m −3 ) intracellular osmolarities than most others (>180 osmol m −3 ). Low osmolarities are related to the presence of flagella and the low energy cost of active water efflux following downhill water influx unconstrained by cell walls covering the plasmalemma, and the low resource cost of cell wall synthesis with the same mechanical degree of safety. One consequence of low intracellular osmolarity is limitation on the concentration of metabolites, that is, substrates and products of enzyme activity. Models of the flux through metabolic pathways, and hence the specific growth rate, using steady-state concentrations of enzymes and metabolites have involved organisms with intracellular metabolite osmolarities >280 osmol m −3 , where the metabolite concentrations are much greater than the total osmolarity of some freshwater algae. Since the protein concentration (mol m −3 ) in the cells and the specific growth rates of freshwater cells with low and with higher intracellular osmolarity are highly similar, the models of trade-offs between enzyme and metabolite concentrations for cells with high intracellular osmolarity need modification for cells with low intracellular osmolarity. The soluble free-radical scavenger ascorbate can constitute as little as 0.2% of the low intracellular metabolite concentration (mol m −3 ) of low-intracellular-osmolarity cells.	en_US
dc.relation.ispartof	Journal of Experimental Botany	en_US
dc.relation.isbasedon	10.1093/jxb/ery254	en_US
dc.subject.classification	Plant Biology & Botany	en_US
dc.subject.mesh	Seaweed	en_US
dc.subject.mesh	Algal Proteins	en_US
dc.subject.mesh	Osmolar Concentration	en_US
dc.subject.mesh	Microalgae	en_US
dc.title	The potential effect of low cell osmolarity on cell function through decreased concentration of enzyme substrates	en_US
dc.type	Journal Article
utslib.citation.volume	20	en_US
utslib.citation.volume	69	en_US
utslib.for	0607 Plant Biology	en_US
utslib.for	0703 Crop and Pasture Production	en_US
utslib.for	0604 Genetics	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
utslib.copyright.status	closed_access
pubs.issue	20	en_US
pubs.publication-status	Published	en_US
pubs.volume	69	en_US

Abstract:

© The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. Some freshwater algae have lower (<130 osmol m −3 ) intracellular osmolarities than most others (>180 osmol m −3 ). Low osmolarities are related to the presence of flagella and the low energy cost of active water efflux following downhill water influx unconstrained by cell walls covering the plasmalemma, and the low resource cost of cell wall synthesis with the same mechanical degree of safety. One consequence of low intracellular osmolarity is limitation on the concentration of metabolites, that is, substrates and products of enzyme activity. Models of the flux through metabolic pathways, and hence the specific growth rate, using steady-state concentrations of enzymes and metabolites have involved organisms with intracellular metabolite osmolarities >280 osmol m −3 , where the metabolite concentrations are much greater than the total osmolarity of some freshwater algae. Since the protein concentration (mol m −3 ) in the cells and the specific growth rates of freshwater cells with low and with higher intracellular osmolarity are highly similar, the models of trade-offs between enzyme and metabolite concentrations for cells with high intracellular osmolarity need modification for cells with low intracellular osmolarity. The soluble free-radical scavenger ascorbate can constitute as little as 0.2% of the low intracellular metabolite concentration (mol m −3 ) of low-intracellular-osmolarity cells.

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http://hdl.handle.net/10453/131089