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I found our Thursday discussion about action potentials and batteries to be very interesting. What we discussed on the scientific level complements most of what I learned in Intro Bio, but the approach is certainly different. While we certainly covered concentration gradients and the transfer of a message via electric actions between sodium and potassium ions in Intro Bio, we never related such a critical biological process to the function of a battery. I decided to do some further searching to see if there was additional information about action potentials behaving as batteries, and this is what I found:

Wikipedia: "Cell membranes that contain ion channels can be modeled as RC circuits to better understand the propagation of action potentials in biological membranes. In such a circuit, the resistor represents the membrane's ion channels, while the capacitor models the insulating lipid membrane. Variable resistors are used for voltage-gated ion channels, as their resistance changes with voltage. A fixed resistor represents the potassium leak channels that maintain the membrane's resting potential. The sodium and potassium gradients across the membrane are modeled as voltage sources (batteries)"

I think this further details the relationship between action potentials and batteries, and thus strengthens our argument. Additionally, a major contributor to the validity of our battery model is, in my opinion, the fact that action potentials can still be produced/measured for some amount of time AFTER the system/organism has died. Clear evidence of this is that students in BMC Intro Bio lab collected action potential data from nerve cords completely cut/removed from earthworms (that died after this 'nerve surgery'). Perhaps the best analogy I can think of is that even when the circuit within a flashlight/battery-powered device ceases to work (for reasons other than dead batteries), one can STILL remove the batteries and use their potential energy to power another device!