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10 Cards in this Set
- Front
- Back
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Describe the physical properties of the cell membrane.
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The cell membrane has two lipid layers, is both fluid and mosaic, is semi-permeable and is studded with differing kinds of proteins.
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What are the 3 most notable reasons a cell's resting membrane potential is negative?
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1.) Na+/K+ ATPase Pump
2.) Proteins (largely negatively charged and trapped inside the cell) 3.) K+ non-gated channels allowing potassium ions to leak out of the cell. |
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What is resting membrane potential?
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Resting membrane potential is a measurable negative voltage all cells have and is a cell's potential for action
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Describe the processes of the Na+/K+ ATPase Pump.
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K+ moves out of the cell as Na+ moves into the cell through the same protein. The movement of the two ions is powered by ATP broken down in the protein.
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What is the ratio at which Na+ and K+ are exchanged?
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Every 2 K+ ions are brought into the cell for every 3 Na+ ions leaving.
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How else does K+ exit the cell (in resting membrane potential)?
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K+ leaves the cell through open channels (no gate) allowing only K+ ions to leave the cell.
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What is ouabain?
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Ouabain is a neurotoxin that blocks the processes of the sodium pump.
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What is hyperpolarization?
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Hyperpolarization is the increasing of a cell's negative voltage. A cell gets hyperpolarized as it is on its downward decline during action potential.
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What is depolarization?
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Depolarization is the process of a cell's voltage becoming more positive. A cell becomes depolarized after it begins its action potential.
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What is the chemical reason for K+ leaking out of the cell through the open gated channels?
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Diffusion causes K+ ions to leak out of the cell because there is more K+ inside the cell than outside.
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