Dear Biology Nerd,
For those who can’t (or just didn’t) see the video, it’s somebody sprinkling salt on some frog legs, which jump around and enjoy a dance despite having no body to go with. I have a pretty simple biological theory on why this happens. Let me break it down for you
First of all, table salt is a chemical called sodium chloride. The sodium and the chloride are bonded together, which is why they are totally safe even though on their own large concentrations are explosive or poisonous, respectively. (Go Google sodium and water reactions. Pretty crazy explosions!) When salt is placed in water, the chloride and sodium separate to form charged particles called ions.
The body uses both sodium and chloride all the time as chemical messengers. One way to use them causes electrical impulses in your neurons. Your neurons have long fibers, called axons, that connect one to another like wiring in an electrical system. Where one of the axons “plugs in” to the next neuron, it’s a synapse.
Synapses are cool because they use chemicals to create electricity, sort of like how a battery works. These ions, when separated, have a charge. Sodium’s is positive. A cell will usually pump sodium out to keep the concentration and thus the voltage that it wants.
The voltage is very important, because in neurons it allows for something called an action potential to occur. The synapses have channels in them that are opened or closed depending on the charge of the environment around them. They will open at a certain voltage and let sodium into the cell. Because this sodium has a positive charge, the voltage in the cell skyrockets upward, creating an electrical impulse as little sodiums pour into the cell. And bada-bing bada-boom, these impulses can be used to tell muscles to move.
So, what does this have to do with frog legs? Basically, the salt releases sodium onto the muscles of the frog legs, which causes an action potential. This makes the frog legs jerk even though there is no frog attached!
The Biology Nerd
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