Activity 1
1. Explain why increasing extracellular K+ reduces the net diffusion of K+ out of the neuron through the K+ leak channels. Your answer: By increasing the extrecellular K+ the net diffiusion of K+ out the neuron through the eak channels is reduced. This is caused by the flow of ions following the concentration gradient of traveling from an area of high concentration to areas of low concentration. The higher concentration gradient would result in a reduced diffusions of K+ ions out of the neuron via the leak channels.
2. Explain why increasing extracellular K+ causes the membrane potential to change to a less negative value. How well did the results compare with your prediction? Your answer: By increasing the extracellular K+ the membrane potential will change to be a less negative value. By adding more extracellular K+ the intracellular K+ will decrease and cause the membrane potential to become less negative. This result in a increased postitve membrane was what we predicted during the experiment.
3. Explain why a change in extracellular Na+ did not significantly alter the membrane potential in the resting neuron? Your answer: A change in the extracellular Na+ did not significantly alter the membrane potential in the resting neuron because of the channels. There are fewer sodium leak channels than compared to potassium leak channels and therefore the Na+ did not alter the membrane potential significantly.
4. Discuss the relative permeability of the membrane to Na+ and K+ in a resting neuron. Your answer: The permeability of the membrane to Na+ and K+ in a resting neuron is different because of the varying number of leak channels. A cell has more potassium leak channels and has a higher permeability compared to the fewer sodium channels resulting in a lower relative permeability.
5. Discuss how a change in Na+ or K+ conductance would affect the resting membrane potential. Your answer: The cells resting membrane potential is