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Unit 1 Practice Problem For section 1. you are to answer the question in the fol

ID: 90931 • Letter: U

Question

Unit 1 Practice Problem For section 1. you are to answer the question in the following manner. 1. Why the right answer is correct 2. Why the incorrect answer is incorrect 3. To do this you will need to use your physiological definitions and reasoning, and structure and function relationships. See example if you are unsure about this process Drawing is helpful! Section 1 1. Consider a typical cell at its resting membrane potential (rest Vm). The membrane temporarily becomes more permeable to Na+ Ena +55mV, resting Vm 60mV Does a chemical force exist, if so in what direction? a. Yes, inward b. Yes, outward No, a chemical force does not exis 2. Consider a typical cell at its resting membrane potential (rest Vm The membrane temporarily becomes more permeable to Na+ Ena +55mV, resting Vm -60mV Does an electrical force exist, if so in what direction? a, Yes, inward. b. Yes, outward c, No. an electrical force does not exist 3. Consider a typical cell at its resting membrane potential (restVm).The membrane temporarily becomes more permeable to Nat +55mV. Vm -60mV What direction will the ion flow? a. Inward b. Outward c. Cannot state from the given information 4. Consider a typical cell at its resting membrane potential (rest Vm). The membrane temporarily becomes more permeable to Nat Ena +55mV, resting Vm -60mV Would you expect the sodium equilibrium potential (Ex) to change? a. No b. Yes, become more negative c. Yes, become more positive 5. Consider atypical cell at its resting membrane potential (rest Vm). The membrane temporarily becomes more permeable to Ena +55mV, resting Vm -60mV Would you expect the membrane potential Cm to change, if so how? a. No b. Yes, become more negative. c. Yes, become less positive d. Yes, become less negative 6. Consider a typical cell at its resting membrane potential Crest Vm. The membrane temporarily becomes more permeable to Nat Ena +55mV, resting Vm 60mV Would you expect the membrane to depolarize, repolarize, hyperpolarize, or no change? a. No change b. De polarize c. Hyperpolarize d. Repolarize

Explanation / Answer

1) In a resting cell, sodium ion concentration is more outside the cell than inside. The extracellular and intracellular concentrations of sodium ion are approximately 140 mEq/L and 12 mEq/L repectively.

There is difference in sodium ion concentration between intracellular and extracellular compartments. Therefore, a chemical force exists (option c is wrong).

The chemical force acts along the concentration gradient. Sodium ion concentration is more outside the cell than inside (option b is wrong).

Since, sodium ion concentration is more outside the cell than inside, chemical gradient exists in inward direction (option a is correct).