permeabilities All cells under resting conditions have a potential difference ac
ID: 3476396 • Letter: P
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permeabilities All cells under resting conditions have a potential difference across their plasma membranes called the , with the inside of the cell charged with respect to the outside current The resting membrane potential exists because of a tiny excess of cell and an excess of ons inside the positive ions outside that are electrically attracted to each other across of the cel plasma membrane The movement of electrical charge is called systems are and the charge carriers in biological ion concentrations negative The bulk of the intracellular and extracellular fluids remain potential In biological systems, membrane potential is measured in the units negatively The magnitude of the resting membrane potential depends on two factors: differences in specific to ions in the intracellular and extracellular fluids and the membrane those ions millivolts The difference in the amount of charge between two locations is called a resting membrane otential neutralExplanation / Answer
All cell under resting condition have a potential difference (pd) across their plasma membrane called the resting membrane potential, with the inside of the cell negatively charged with respect to outside
as their are two type of membrane potential present 1) resting membrane potential 2) graded potential
Resting membrane potential results from a small build up of negatively charged ion in cytosol , and an equal amount of positively charged ion in ecf (extra cellular fluid) outside the cell
Ecf contains 1 Na+ and 1 Cl- in contrast
Cytosol contains 2 phosphate anion and amino acid( -ve charge) and 1 K+ ions
The resting membrane potential exist because of a tiny excess of negative ion inside the cell and an excess of positive ion ouside that are electrically attracted to each other across the plasma membrane of the cell
Factor contributing the resting membrane potential are
1)unequal distribution of ions in ecf and cytosol
The plasma membrane has more K+ leak channel them Na+ , so more amount of K+ move down its concentration gradient out of the cell then the amount of Na+ enter into the cell ( so more +be charge goes outside as compare to less +ve charge enter in cell)
2) inability of anion to leave the cell
As more anion (-ve charge) are bound to non diffusable compound for eg. Phosphate bound to adenine in ATP
3) electrogenic nature of Na+/K+ ATPs channel
As this channel expel 3 Na+ for each 2 K+ imported so inner charge become more negative in comparison with outside charge
The movement of electric charge is called current and the charge carriers in biological systems are ions
As simple movement of charges are called current and as the electricity flows through wire by movement electron, in biological systems the ions contains charges so movement of charges results in electrical flow
In biological systems ,membrane potential measued in millivolt
Its the unit of potential difference in biological systems
the magnitude of resting membrane potential depends on two fector : difference in specific ion concentration in the intracellular and extracellular fluid and membran permiability to those ions
As previously discussed the concentration of ion differ inside and outsioutside the membrane thats why the distribution of ions intracelluarly and extracellularly differs for eg. The plasma membrane more permiable to Na+ so amount of Na+ leaves is higher then amount of K+ enters
the less positively charged ion presnt intracellularly then positively charged ion present extracellularly, inside becomes negative and outside becomes positive also refer privious eg. amount of ions on both side of plasma membrane
the difference in the amount of charge between two locations is called a potential.
For eg. You heard about H+ ions buildup inside the mitochondrial lumen and because of this the H+ concentration deacreses outside the lumen in mitochondria this results into potential gradient
when H+ moves down its concentration gradient (lumen to outside) ATP are generated
The bulk of intracellular and extracellular fluid remain neutral
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