A mammalian nerve cell initially rests at −80 mV. A drug lowers intracellular K⁺ from 150 to 55 mmol/L while external K⁺ is unchanged. Use R=8.315 J/(mol K),37°C,F=96500 C/mol and the potassium equilibrium model. Find the nearest new membrane potential in mV.
Nernst potential is (RT/F)ln(Kout/Kin). Taking the change cancels the unknown unchanged external concentration: ΔV=(RT/F)ln(150/55). At about 310 K, RT/F≈26.71 mV and ln(150/55)≈1.0033, giving ΔV≈+26.8 mV. New potential≈−80+26.8=−53.2 mV, nearest C.
More Biopotentials and Electrodes questions
GATE 2020 BM Q65– A cell is driven by current i(t)=u(t). Its linear membrane model has impulse response…
GATE 2026 BM Q43– An EEG PSD has band-average values (μV²/Hz): 0.4–4 Hz:3; 4–8:4; 8–13:8; 13–30:5; 30–100:3.…
GATE 2026 BM Q44– Match ECG waveforms X,Y,Z in Panel 1 with (i) normal condition, (ii) atrial flutter, (iii)…
GATE 2025 BM Q28– In a human ECG, atrial repolarization is usually masked by which component?
GATE 2025 BM Q31– A low-pass filter with 250 Hz cutoff is NOT suitable for recording which signal?
GATE 2024 BM Q45– To isolate alpha EEG, the diagram cascades ideal high-pass cutoff fh,low-pass cutoff…