Transcription
Did you know that lobsters are considered biologically immortal? If you were a lobster, as long as you had enough food and managed to avoid predators, you could keep growing endlessly and technically never die. There's a lobster named Big George that lived for more than 140 years.
But there's a catch. Lobsters don't actually live forever. The reason they eventually die is that their soft bodies keep growing while their hard shells do not. To manage this, they must molt, shedding their old exoskeleton and growing a new one. The problem is as lobsters get bigger, this process demands more and more energy. Eventually, it becomes too exhausting and they die.
So why don't lobsters age the way humans do? The reason is human cells can only divide about 40 times before they stop replicating. Partly due to structures called telomeres, protective caps at the ends of our chromosomes. Each time a cell divides, these telomeres shorten until they're too small to protect the DNA and the cell can no longer divide.
Lobsters, however, have a special enzyme called telomerase that repairs and rebuilds these telomeres, letting them effectively bypass the normal aging process.