• Its effects are similar to proton ionophores such as FCCP, which disrupt mitochondrial transmembrane electrochemical gradients. (wikipedia.org)
  • When the membrane potential is considered, PCFT generates substantial transmembrane electrochemical-potential gradients at extracellular pH levels relevant to the tumor microenvironment. (aspetjournals.org)
  • At pH 7.0, there was a substantial chemical gradient for methotrexate that decreased as the extracellular pH was increased. (aspetjournals.org)
  • A chemical gradient was still detected at pH 7.4 in the usual HEPES-based transport buffer in contrast to what was observed in a bicarbonate/CO 2 -buffered medium. (aspetjournals.org)
  • An antifolate chemical gradient was also detected in bicarbonate buffer at pH 6.9 versus 7.4, also suppressed by carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone. (aspetjournals.org)
  • 2) Chemical diffusion occurs in the presence of a concentration gradient. (wikibooks.org)
  • When ΔG is positive the transport is active, an input of energy is needed to move a molecule up a concentration gradient, contrary to ΔG being negative the transport is passive, which means that such molecules will pass through a membrane down their own gradient, simple diffusion. (wikibooks.org)
  • By far the best-described are GLUT class I transporters (GLUTs 1 - 4 and 14) and GLUT class II transporters (GLUTs 5, 7, 9 and 11), which mediate equilibrative, energy independent membrane transport of hexose sugars down their concentration gradient. (biomedcentral.com)
  • The electrical membrane potential ( V m ) is one of the components of the electrochemical potential of protons across the biological membrane (proton motive force), which powers many vital cellular processes, and V m also plays a role in signal transduction. (biorxiv.org)
  • For the latter, V m adds up to the chemical potential of protons, arising from their concentration difference across the membrane, to result in the proton electrochemical gradient, so called proton motive force (PMF). (biorxiv.org)
  • The concentration gradient favors influx of Na and efflux of K, but a membrane potential of -70 mV potential favors influx of cations of any kind. (biologydiscussion.com)
  • Insertion is independent of the proton motive force, and proteoliposomes containing only YidC catalyze the membrane insertion of F 0 c in its native transmembrane topology whereupon it assembles into large oligomers. (rupress.org)
  • Ionophores are structures which work as transporters and dissipate ion gradients. (biologydiscussion.com)
  • Passive transport does not require an expenditure of metabolic energy, and materials flow down the concentration gradient. (biologydiscussion.com)
  • Diffusion of water down its concentration gradient is called osmosis. (biologydiscussion.com)
  • Thus when considering transport of ions we must take into ac-count their concentration gradient as well as the electrical gradient, the combined potential is called electrochemical potential. (biologydiscussion.com)
  • The flavonol substrates were early examples of excited state intramolecular proton transfer (ESIPT) phenomena, in which photoexcitation causes an H-atom exchange between the adjacent hydroxyl and ketone, generating an oxidopyrylium emissive state. (bvsalud.org)