Dear Annika,
I’d love to read a creepy science fiction story where people dissolve.
I asked my friend Anders Omsland if that could happen. He’s a biomedical researcher at Washington State University.
He told me a lysosome is a specialized compartment in a cell. It’s like a little sack of digestive enzymes. Those are proteins that break stuff down. Our cells use lysosomes to help destroy germs or recycle old or messed up cell parts.
Lysosomes are basically the cell’s trash and recycling centers.
“I don’t think it’s possible for lysosomes to all pop at the same time,” Omsland said. “They don’t really explode in the first place. Their function is regulated in a very orchestrated, orderly process.”
Here’s how lysosomes work.
Let’s say you forget to wash your hands and germs enter your body. With any luck, an immune cell—called a macrophage—senses the germ. The macrophage scoops it up. It holds the germ in a sack-like bubble. That’s called a vesicle, or more precisely, a phagosome. Then the phagosome fuses with a lysosome to form a phagolysosome. Inside, digestive enzymes from the lysosome help destroy the germ.
Or imagine that one of your cells makes hemoglobin. That’s a protein that carries oxygen in your blood. Normally, proteins work because of the way they’re folded. A misfolded protein probably won’t work. So, your cells scan for errors. They tag messed-up proteins. Those get picked up and taken to a lysosome. Just like with germs, the lysosome breaks down the misfolded protein. Then it recycles the parts so the cell can try again.
Lysosomes are so important that mammal cells usually have hundreds of them.
Having all those pockets of digestive enzymes isn’t risky. Your body evolved a fail-safe to prevent accidents.
“These processes activate in specific and orderly ways—so we don’t get eaten up by our own lysosomal enzymes,” Omsland said. “One specific condition that activates degradative enzymes, often referred to as acid hydrolases, is acidic pH.”
The inside of a lysosome is acidic. And those digestive enzymes only work in an acidic environment.
Cells are full of goo—called cytosol. It’s neutral and not acidic. So, even if the lysosomes leaked, nothing would happen. It isn’t acidic enough to turn on the enzymes.
Rarely, people are born with lysosomes that don’t function properly. Their cells can’t remove waste and toxic stuff. That can make them sick.
So, scientists don’t worry about lysosomes bursting. They don’t stress about people dissolving. But they are concerned about people whose lysosomes don’t work. They’re figuring out ways to fix the problem.
And that’s pretty vesi-cool.
Sincerely,
Dr. Universe