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3 Cards in this Set
- Front
- Back
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How do people measure ion channel currents. |
- patch-clamp technique - this measures single channel currents - patch-clamp used to answerfollowing questions: 1.Howmuch current does a single channel carry? 2.Howlong does a channel stay open? 3.Whatactivates the channel? |
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Explain single channel currents. |
- Channels alternate between open& closed states - measurements are “microscopic currents” and measured in picoamperes = pA (10-12 A) - In a diagram, a closed ion channel measures as a straight line - an open channel is displayed as dips (downward deflections means current in flowing in) - the convention for membrane current: outward flux of cations is positivecurrentards/auto-save |
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How is patch clamp technique usedto quantify channel conductance? |
- using ohm's law: States: “current flows through aconductor is directly proportional to the potential difference across it” V =IR - systematically change the potentialacross the cell membrane andmeasure the resulting current |
