Microbes 101: Bacteria

When most people think of microbes, they think of bacteria. Bacteria are some of humanity’s most intimate partners. They live in every crevice of our bodies and help us with our daily functions. With every meal, bacteria in our guts help digest our food. When we perspire, they draw nutrients from our sweat, in the process producing that delightful smell we call body odor. They are also some of our most deadly foes, plague-causing and flesh-eating.

What makes bacteria bacteria? Animal and plant cells are chock-full of organelles: the tiny, specialized parts that carry out discrete functions, similar to organs in a body but on a cellular scale. If a cell has organelles, it is a eukaryotic cell. Bacteria lack organelles; they are prokaryotes. Although we far surpass bacteria in structural complexity, humans and other multicellular creatures rely heavily on the diverse chemical capabilities of bacteria. If we think of the Tree of Life as having three big trunks, bacteria have one of those trunks all to themselves, with a myriad of branches. They carry out a range of biochemical processes that are deeply integrated into our own human physiology: by transferring nutrients and sending signals between themselves and with our own human cells, they are a crucial component of our bodies and are required for normal function. They cover the rest of the planet as well and are pivotal players in nutrient cycles, decomposition, and many other processes fundamental to creating and sustaining the world we live in.

*Image credits: Wikimedia Commons

I Contain Multitudes is a multi-part video series dedicated to exploring the wonderful, hidden world of the microbiome. The series is hosted by science writer Ed Yong and produced by HHMI Tangled Bank Studios in association with Room 608.