Related Experiment Video
Updated: May 5, 2026

Measuring Fluxes of Mineral Nutrients and Toxicants in Plants with Radioactive Tracers
Published on: August 22, 2014
The regulation of K(+) influx in excised barley roots : Relationships between K(+) influx and electrochemical
1Department of Botany, University of British Columbia, V6T 1W5, Vancouver, B.C., Canada.
Abstract:
The electrochemical potential differences [Formula: see text] for potassium, between excised barley (Hordeum vulgare L.) roots and external media containing 0.05 mM KCl+0.5 mM CaSO4, were determined over a 4-h period during which initially low-K(+) roots accumulated K(+) by pretreatment in 50 mM KCl plus 0.5 mM CaCl2. This pretreatment resulted in increased internal [K(+)], decreased K(+) influx (as measured from 0.05 mM KCl+0.5 mM CaSO4) and decreased values of [Formula: see text]. These observations indicate that the decline of K(+) influx associated with increased internal K(+) concentration cannot be accounted for by passive adjustment to the electrochemical gradient for this ion.
More Related Videos
Related Concept Videos
Resting Potential Decay
At rest, the K+ is the main ion that moves across the membrane...
Short-distance Transport of Resources
Water and Mineral Acquisition
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential....
The Resting Membrane Potential
Resting Membrane Potential
The Inside of a Neuron is More Negative
The membrane potential of a cell can be measured by inserting a microelectrode into a cell and comparing the charge to a reference electrode in the extracellular fluid. The...

