Salt in the Cell Changes the Rules of the Game express
In a glass of salty water, even if it sits perfectly still, something is always happening. Tiny salt particles, ions, float and collide, sending ripples through the water. These ripples are invisible, but they create a force that attracts or repels nearby objects.
Previously, it was thought that this force only acts over very short distances, as if it quickly fades out. But it turns out that in salty water, it extends further. Inside a living cell, which also contains salt, this force can reach protein filaments — actin fibers that serve as the cell's skeleton, much like bones do for the body.
The scientists created a model resembling biological matter and saw that at distances important for the cell, it is this long-range part of the force that plays the main role. This means that the cell might be using the invisible ripples of salty water for its own needs — for example, to assemble or disassemble its skeleton.
The ripples in a glass of salty water are not just a curiosity. The same ripples might be keeping the insides of every living cell in order.
Inside a cell, the salt concentration is roughly similar to that of seawater, and actin fibers are thousands of times thinner than a human hair, and at that scale, invisible ripples become a noticeable force.