BIOC32H3 Study Guide - Final Guide: Resting Potential, Protein Kinase A, Excitatory Synapse
Document Summary
Lecture 2: excitable cells (cid:1005)9(cid:1004)(cid:1006): ber(cid:374)stei(cid:374)"s membrane theory says at rest, more k inside the cell than outside, creating gradient. The membrane is impermeable to larger and polar molecules. The potential difference between two points is the energy needed to drive ions between two compartments (ie- the driving force). Note that voltage (potential difference) as measured by a voltmeter is relative to the grounding electrode. Therefore, the membrane potential is the potential inside the cell with respect to potential outside. The inside of the cell is usually more negative due to the presence of negatively charged proteins, so resting membrane potential (as opposed to action potential) is an equilibrium point around -70 mv (varies from. In an excitable cell, the resting membrane potential can be changed, by letting ions pass through the cell via channels. The primary channels for na+ and k+ flow in these cells are voltage-gated: they open and close at specific voltages.
