The woman in the photo above, Elizabeth Blackburn, is a molecular biologist who won the Nobel Prize in 2009 for her role in discovering an enzyme called telomerase. Its job is to replenish the bits of DNA on the ends of your chromosomes, which are called telomeres.

But wait, there's a fun analogy! Telomeres are like the plastic caps on the ends of your shoelaces that help keep them tidy. (And yes, some of you may know that those shoelace caps are called "aglets," but wow — let's try to keep this post from needing a special glossary at the end of it.)

The point is, just like your shoelaces, you want the caps on your chromosomes to stay in place as long as possible. When the caps on your shoelaces wear down, the ends get all frayed and it's hard to tie your shoes without a lot of swears.