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In essence, the Goldman formula expresses the membrane potential as a weighted average of the reversal potentials for the individual ion types, weighted by permeability. (Although the membrane potential changes about 100 mV during an action potential, the concentrations of ions inside and outside the cell do not change significantly.
They also reduce the mitochondrial membrane potential in mammalian cells, which reduces production of reactive oxygen species (ROS). In contrast to UCP1 and UCP3, which are primarily expressed in adipose and smooth muscle, UCP2 is expressed on many different tissues [ 6 ] including the kidney, liver, GI tract, brain, and skeletal muscle.
[1] [2] There is debate as to whether or not this channel is expressed in the cell surface membrane. [3] [4] [5] This major protein of the outer mitochondrial membrane of eukaryotes forms a voltage-dependent anion-selective channel (VDAC) that behaves as a general diffusion pore for small hydrophilic molecules.
MPT causes mitochondria to become permeable to molecules smaller than 1.5 kDa, which, once inside, draw water in by increasing the organelle's osmolar load. [34] This event may lead mitochondria to swell and may cause the outer membrane to rupture, releasing cytochrome c. [34]
The inner mitochondrial membrane is compartmentalized into numerous folds called cristae, which expand the surface area of the inner mitochondrial membrane, enhancing its ability to produce ATP. For typical liver mitochondria, the area of the inner membrane is about five times as large as that of the outer membrane.
The protons are pumped from the mitochondrial matrix to the IMS by these respiratory complexes. As a result, an electrochemical gradient is generated, which is combined by forces due to a H + gradient (pH gradient) and a voltage gradient (membrane potential). The pH in the IMS is about 0.7 unit lower than the one in the matrix and the membrane ...
During an action potential, the depolarization is so large that the potential difference across the cell membrane briefly reverses polarity, with the inside of the cell becoming positively charged. The change in charge typically occurs due to an influx of sodium ions into a cell, although it can be mediated by an influx of any kind of cation or ...
Mitochondria present in all cells in the human body require a resting membrane potential of the inner mitochondrial membrane to synthesize adenosine triphosphate (ATP). This membrane polarity is established through a series of proton pumps transporting hydrogen ions into the mitochondrion.