How do we know so much about cells and their functions?

Question

How did scientists figure out what functions different parts of cells have, and how they work together?

In: Biology

Answer 1

Microscopes, testing, and development of storage and analysis of cells (particularly refrigeration/freezing).

Robert Hooke, who lived at the same time as Isaac Newton, helped develop what we would call the first optical microscope, and used it to discover that living things are made of cells. (Indeed, they were called “cells” because he was looking at plants, which have boxy units like the places where prisoners or monks live, hence “cells”). Even very early on, people could see that cells had internal parts. The analogy between internal cell parts and internal body parts was so obvious, people just *called* those parts “organs” for a long time. Later, we learned they definitely didn’t look or behave like actual body organs in miniature, which was a theory for a time, so the cell-parts were called “organelles” to distinguish them.

As the decades (and then centuries) passed, we learned more. Golgi, for example, identified the famous Golgi apparatus *very* early, around 1830, but it wasn’t until the early 20th century that he was proven right (people thought his structure was just an artifact of the way he collected his data.)

Finally, in the mid 20th century, we started to have the ability to determine what the chemical makeup of these organelles was. We could see small enough things to detect most of the parts, and with advanced technology, we could find out what elements were in these things and in what arrangements. This allowed us to finally determine what all of the different organelles actually do. As one example, we only learned what DNA was in the middle of the 20th century, even though we had known that chromosomes existed and were responsible for genetic inheritance around fifty years earlier.

Lots and lots of people looking as closely as they could at living and preserved cells for many, many years, plus modern technology to let us find out what chemical compounds organelles were made of.