In principle, an ion channel needs no more than a single gate, but a pump requires at least two gates that open and close alternately to allow ion access from only one side of the membrane at a time. In the Na,K-ATPase pump, this alternating gating effects outward transport of three Na ions and inward transport of two K ions, for each ATP hydrolysed, up to a hundred times per second, generating...

The active component of phosphate solutions, in relation to promoter action on oxidising enzymes, is the PO(4) (''') ion. This is shown by the demonstration of a hyperbolic relationship between per cent production of CO(2) (of Elodea) and pPO(4), the measure of the phosphate ion potential. This is consistent with the rate of respiration as affected by changing pPO(4) through change of total pho...

We st udy th e sequences generated by neuronal recurrence equat ions of th e form X n = l [~l then there is a neuronal recurrence equat ion with memory length kr that generates a sequence of period lcmlp «,...

The Na-K-ATPase is an energy-transducing ion pump that converts the free energy of ATP into transmembrane ion gradients. It also serves as a functional receptor for cardiotonic steroids such as ouabain and digoxin. Binding of ouabain to the Na-K-ATPase can activate calcium signaling in a cell-specific manner. The exquisite calcium modulation via the Na-K-ATPase is achieved by the ability of the...

A number of compounds related to TEA+ (tetraethylammonium ion) were injected into squid axons and their effects on gK (the potassium conductance) were determined. In most of these ions a quaternary nitrogen is surrounded by three ethyl groups and a fourth group that is very hydrophobic. Several of the ions cause inactivation of gK, a type of ionic gating that is not normally seen in squid axon;...

As for Li- and Na-ion batteries, the electrolyte reactivity (i.e., salt solvent decomposition) also plays a crucial role in electrochemical performance of K-ion batteries (KIBs). However, X-ray photoelectron spectroscopy (XPS) analysis solid interphase (SEI) KIBs remains based on Li-ion literature so far. This may lead to incorrect interpretations results considering that first ionization poten...

Normal human red blood cells, when exposed briefly to acetylphenylhydrazine (APH), acquire Heinz bodies and a propensity for net ion and water loss upon subsequent incubation in an APH-free medium of physiologic sodium and potassium (K) content. The cells can be protected from APH damage by previous deoxygenation. The ion and water loss depend on the presence of a K gradient from cell to medium...

Recent studies using mutagenesis to alter ion channel function have shown that the selectivity filter in many ion channels is formed by pore loops, relatively short polypep-tide segments that extend into an aqueous pore from one side of the membrane. Why do ion channels use pore loops to form their selective ion-binding sites? The purpose of this perspective is to address this question in the c...

When exposed to low temperatures, many insect species enter a reversible comatose state (chill coma), which is driven by a failure of neuromuscular function. Chill coma and chill coma recovery have been associated with a loss and recovery of ion homeostasis (particularly extracellular [K(+)], [K(+)]o) and accordingly onset of chill coma has been hypothesized to result from depolarization of mem...