10 . Which one of the following statements is NOT true about the resting potential? (28.3) [Hint]
A. The neuron's plasma membrane is much more permeable to potassium than to sodium.
B. The concentration of sodium is much higher inside the cell than outside.
C. The sodium-potassium pump plays a role in maintaining the resting potential.
D. Inside the cell, the concentration of potassium is much higher than the concentration of sodium.
E. All of these are true statements.
12 . A drug that causes potassium to leak out of a neuron, increasing the positive charge on the outside, would _____.
A.make it easier to trigger action potentials in the neuron
B.cause the cell to release its neurotransmitter
C.speed up nerve signals traveling the length of the cell
D.act as a stimulant
E.inhibit transmission of nerve signals by the neuron
10. The correct answer is B. The concentration of sodium is much higher inside the cell than outside. This statement is NOT true about the resting potential. In fact, the concentration of sodium is much higher outside the cell than inside.
12. The correct answer is E. inhibit transmission of nerve signals by the neuron.
10. The correct answer is B. The concentration of sodium is much higher inside the cell than outside.
12. The correct answer is A. make it easier to trigger action potentials in the neuron.
To find the answer to question 10, we need to determine which statement is NOT true about the resting potential.
Statement A: The neuron's plasma membrane is much more permeable to potassium than to sodium. This statement is true. The resting potential is maintained by the selective permeability of the neuron's plasma membrane, which allows more potassium ions to pass through than sodium ions.
Statement B: The concentration of sodium is much higher inside the cell than outside. This statement is not true. In the resting state, the concentration of sodium is higher outside the cell compared to the inside.
Statement C: The sodium-potassium pump plays a role in maintaining the resting potential. This statement is true. The sodium-potassium pump actively transports sodium ions out of the cell and potassium ions into the cell, contributing to the establishment of the resting potential.
Statement D: Inside the cell, the concentration of potassium is much higher than the concentration of sodium. This statement is true. In the resting state, the concentration of potassium is higher inside the cell compared to the outside.
Based on the evaluation of statements A, B, C, and D, the answer to question 10 is E. All of these statements are true about the resting potential.
For question 12, we need to determine the effect of a drug that causes potassium to leak out of a neuron, increasing the positive charge on the outside.
Option A: Make it easier to trigger action potentials in the neuron. This is true. The increased positive charge on the outside would lead to a depolarization of the neuron, making it easier to trigger an action potential.
Option B: Cause the cell to release its neurotransmitter. This is false. The release of neurotransmitters is usually triggered by an action potential, and an increased positive charge on the outside does not necessarily lead to neurotransmitter release.
Option C: Speed up nerve signals traveling the length of the cell. This is false. The speed of nerve signals is primarily determined by the properties of the axon, such as its diameter and myelination, and not by the positive charge on the outside.
Option D: Act as a stimulant. This is true. By increasing the positive charge on the outside and potentially facilitating the occurrence of action potentials, the drug could have a stimulating effect on the neuron.
Option E: Inhibit transmission of nerve signals by the neuron. This is false. While the drug may affect the behavior of the neuron, it does not necessarily inhibit the transmission of nerve signals.
Based on the evaluation of options A, B, C, D, and E, the answer to question 12 is D. The drug would act as a stimulant.