Question
Assertion: The resting membrane potential (RMP) is influenced by the presence of negatively charged proteins and phosphate ions inside the cell.
Reason: The Nernst equation is used to calculate the diffusion potential for ions based on their concentration gradient across the cell membrane.
Select the most appropriate option regarding the assertion and reason:
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Both the assertion and reason are true, but the reason is not the correct explanation for the assertion.
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| B. |
Both the assertion and reason are true, and the reason is the correct explanation for the assertion.
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| C. |
The assertion is true, but the reason is false.
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| D. |
The assertion is false, but the reason is true.
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Show Answer
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Correct Answer » A
Explanation
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Assertion: The resting membrane potential (RMP) is indeed influenced by negatively charged proteins and phosphate ions inside the cell. These anions contribute to the overall negative charge within the cell, which affects the RMP.
Reason: The Nernst equation is correctly used to calculate the diffusion potential for individual ions (such as K+, Na+, or Cl−) based on their concentration gradients. However, it does not specifically address the influence of non-permeable ions like proteins and phosphate ions on the RMP.
Thus, both statements are true, but the Nernst equation is not directly related to the effect of impermeant anions like proteins and phosphate ions on RMP. Therefore, the reason is not the correct explanation for the assertion.
Resting membrane potential (RMP) is mainly determined by the distribution of ions (K⁺, Na⁺, Cl⁻) across the cell membrane.
– Negatively charged intracellular proteins and phosphate ions (organic anions) contribute to the overall negative charge inside the cell.
– These impermeant anions help maintain the negative internal environment but do not directly determine the RMP alone.
