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Which statement describes the membrane potential at the peak of an action potential?
- a)The membrane potential is the same as the Na+ equilibrium potential.
- b)The membrane potential is slightly less positive than the Na+ equilibrium potential.
- c)The membrane potential is slightly more positive than the Na+ equilibrium potential.
- d)The membrane potential is much more positive than the Na+ equilibrium potential.
Correct answer is option 'B'. Can you explain this answer?
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Which statement describes the membrane potential at the peak of an act...
During the peak of an action potential, the membrane potential is not exactly equal to the Na+ equilibrium potential but rather slightly less positive. This is because the voltage-gated Na+ channels begin to close, leading to a decrease in the influx of Na+ ions and a subsequent repolarization of the membrane. The membrane potential returns to a negative value during the repolarization phase. Thank you for pointing out the error.
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Which statement describes the membrane potential at the peak of an act...
Understanding Membrane Potential at the Peak of an Action Potential
At the peak of an action potential, the membrane potential changes significantly due to the influx of sodium ions (Na+). Here’s a detailed explanation of why option 'B' is the correct answer.
1. Action Potential Overview
- An action potential is a rapid rise and fall in membrane potential.
- It typically consists of three phases: depolarization, repolarization, and hyperpolarization.
2. Na+ Equilibrium Potential
- The Na+ equilibrium potential (ENa) is the membrane potential at which there is no net movement of Na+ ions across the membrane.
- This potential is usually around +60 to +70 mV, depending on the concentration gradients of sodium and potassium ions.
3. Membrane Potential at the Peak
- At the peak of the action potential, the membrane potential reaches its maximum value, often around +30 to +40 mV.
- This is due to the rapid influx of Na+ ions through voltage-gated sodium channels.
4. Why Option 'B' is Correct
- At the peak, the membrane potential is indeed very positive but not equal to the Na+ equilibrium potential.
- Because there are still some K+ channels open and the membrane is not perfectly permeable to only Na+, the peak potential remains slightly less positive than the Na+ equilibrium potential.
5. Conclusion
- Thus, the membrane potential at the peak of an action potential is slightly less positive than the Na+ equilibrium potential, making option 'B' the correct choice.
Understanding these dynamics is crucial for grasping neuronal signaling and the role of ion channels in action potentials.
At the peak of an action potential, the membrane potential changes significantly due to the influx of sodium ions (Na+). Here’s a detailed explanation of why option 'B' is the correct answer.
1. Action Potential Overview
- An action potential is a rapid rise and fall in membrane potential.
- It typically consists of three phases: depolarization, repolarization, and hyperpolarization.
2. Na+ Equilibrium Potential
- The Na+ equilibrium potential (ENa) is the membrane potential at which there is no net movement of Na+ ions across the membrane.
- This potential is usually around +60 to +70 mV, depending on the concentration gradients of sodium and potassium ions.
3. Membrane Potential at the Peak
- At the peak of the action potential, the membrane potential reaches its maximum value, often around +30 to +40 mV.
- This is due to the rapid influx of Na+ ions through voltage-gated sodium channels.
4. Why Option 'B' is Correct
- At the peak, the membrane potential is indeed very positive but not equal to the Na+ equilibrium potential.
- Because there are still some K+ channels open and the membrane is not perfectly permeable to only Na+, the peak potential remains slightly less positive than the Na+ equilibrium potential.
5. Conclusion
- Thus, the membrane potential at the peak of an action potential is slightly less positive than the Na+ equilibrium potential, making option 'B' the correct choice.
Understanding these dynamics is crucial for grasping neuronal signaling and the role of ion channels in action potentials.
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Which statement describes the membrane potential at the peak of an action potential?a)The membrane potential is the same as the Na+ equilibrium potential.b)The membrane potential is slightly less positive than the Na+ equilibrium potential.c)The membrane potential is slightly more positive than the Na+ equilibrium potential.d)The membrane potential is much more positive than the Na+ equilibrium potential.Correct answer is option 'B'. Can you explain this answer? for MCAT 2025 is part of MCAT preparation. The Question and answers have been prepared according to the MCAT exam syllabus. Information about Which statement describes the membrane potential at the peak of an action potential?a)The membrane potential is the same as the Na+ equilibrium potential.b)The membrane potential is slightly less positive than the Na+ equilibrium potential.c)The membrane potential is slightly more positive than the Na+ equilibrium potential.d)The membrane potential is much more positive than the Na+ equilibrium potential.Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for MCAT 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which statement describes the membrane potential at the peak of an action potential?a)The membrane potential is the same as the Na+ equilibrium potential.b)The membrane potential is slightly less positive than the Na+ equilibrium potential.c)The membrane potential is slightly more positive than the Na+ equilibrium potential.d)The membrane potential is much more positive than the Na+ equilibrium potential.Correct answer is option 'B'. Can you explain this answer?.
Which statement describes the membrane potential at the peak of an action potential?a)The membrane potential is the same as the Na+ equilibrium potential.b)The membrane potential is slightly less positive than the Na+ equilibrium potential.c)The membrane potential is slightly more positive than the Na+ equilibrium potential.d)The membrane potential is much more positive than the Na+ equilibrium potential.Correct answer is option 'B'. Can you explain this answer? for MCAT 2025 is part of MCAT preparation. The Question and answers have been prepared according to the MCAT exam syllabus. Information about Which statement describes the membrane potential at the peak of an action potential?a)The membrane potential is the same as the Na+ equilibrium potential.b)The membrane potential is slightly less positive than the Na+ equilibrium potential.c)The membrane potential is slightly more positive than the Na+ equilibrium potential.d)The membrane potential is much more positive than the Na+ equilibrium potential.Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for MCAT 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which statement describes the membrane potential at the peak of an action potential?a)The membrane potential is the same as the Na+ equilibrium potential.b)The membrane potential is slightly less positive than the Na+ equilibrium potential.c)The membrane potential is slightly more positive than the Na+ equilibrium potential.d)The membrane potential is much more positive than the Na+ equilibrium potential.Correct answer is option 'B'. Can you explain this answer?.
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Which statement describes the membrane potential at the peak of an action potential?a)The membrane potential is the same as the Na+ equilibrium potential.b)The membrane potential is slightly less positive than the Na+ equilibrium potential.c)The membrane potential is slightly more positive than the Na+ equilibrium potential.d)The membrane potential is much more positive than the Na+ equilibrium potential.Correct answer is option 'B'. Can you explain this answer?, a detailed solution for Which statement describes the membrane potential at the peak of an action potential?a)The membrane potential is the same as the Na+ equilibrium potential.b)The membrane potential is slightly less positive than the Na+ equilibrium potential.c)The membrane potential is slightly more positive than the Na+ equilibrium potential.d)The membrane potential is much more positive than the Na+ equilibrium potential.Correct answer is option 'B'. Can you explain this answer? has been provided alongside types of Which statement describes the membrane potential at the peak of an action potential?a)The membrane potential is the same as the Na+ equilibrium potential.b)The membrane potential is slightly less positive than the Na+ equilibrium potential.c)The membrane potential is slightly more positive than the Na+ equilibrium potential.d)The membrane potential is much more positive than the Na+ equilibrium potential.Correct answer is option 'B'. Can you explain this answer? theory, EduRev gives you an
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