We couldn’t survive without proteins. They’re essential molecules that provide cells with structure, aid in chemical reactions, support communication, and much more. Portion out protein numbers with us below!

10 Trillion

That’s how many proteins scientists estimate are in each human cell.

229,378

That’s how many structures researchers shared with the scientific community through the Protein Data Bank (PDB) from its establishment in 1971 to the end of 2024. The PDB is a global repository for 3D structural data of proteins, DNA, RNA, and even complexes these biological molecules form with medicines or other small molecules.

42

That’s the percent of your body weight (not counting water) that’s made up of proteins.

"I found a passion for both biology and chemistry in high school and thought, Well, that must mean I'm a biochemist! Luckily my naïve thought was correct. I am a biochemist," says Bil Clemons,
Ph.D. He's a professor of biochemistry at the California Institute of Technology (Caltech) in Pasadena, where he's been teaching and running a lab for nearly 20 years.

A Path to Research

Dr. Clemons doesn't remember a time when he wasn't interested in science or curious about the world. "I think, fundamentally, that's what being a scientist is: being curious about how the world works," he says. As a child, he'd open seed pods to see the insides or take toys apart to see how their tiny motors worked. He couldn't always figure out how to put the toys back together, though, which led to his parents warning him not to ruin his siblings' new toys on Christmas morning.

Anesthesia is a treatment that prevents patients from feeling pain during procedures like surgery, medical tests, and dental work. Anesthesiologists are doctors who have been specifically trained to give medicines used for anesthesia, which are called anesthetics.

Depending on the procedure they’re having, patients receive different types of anesthesia:

Haley Bridgewater, a graduate student at Boise State University in Idaho, is sure she wants to continue studying infectious diseases after she graduates with her Ph.D., but she's finding it difficult to choose a specific topic within that branch of biomedical science. "My problem is that I like them all. The more I look into specific research topics to narrow down my options, the longer my list of potential topics grows," she says.

Haley's early introduction to science wasn't related to the biological sciences at all. She grew up in Los Alamos, New Mexico, where her dad studied nuclear chemistry. Discussions about chemistry, physics, and rockets surrounded her, and she would often stare up at the night sky to catch a glimpse of a meteor shower or the International Space Station passing by. But she was even more curious about what was below her feet: What makes an insect different from a rock? What does the microscopic world look like? She received a microscope one year for her birthday and carried it with her everywhere so she could try to answer these questions.

Global Experiences

Haley took an advanced biology class in high school, where she learned not only about the living world, but also the many exciting scientific careers available, such as becoming a researcher. She moved to Tacoma, Washington, and earned a bachelor's degree from Pacific Lutheran University (PLU), where she majored in biology and global religion.

Cells rely on garbage and recycling systems to keep their interiors neat and tidy. If it weren't for these systems, cells could look like microscopic junkyards—and worse, they might not function properly. So constant cleaning is a crucial biological process, and if it goes wrong, accumulated trash can cause serious problems.

Proteasomes: Cellular Garbage Disposals

One of the cell's trash processors is called the proteasome. It breaks down proteins, the building blocks and mini-machines that make up many cell parts. The barrel-shaped proteasome disassembles damaged or unwanted proteins, breaking them into bits that the cell can reuse to make new proteins. In this way, the proteasome is just as much a recycling plant as it is a garbage disposal.

“Curiosity was a central theme in my learning process,” says Sudha Chakrapani, Ph.D., a professor and chair of the department of pharmacology at Case Western Reserve University in Cleveland, Ohio. As a high schooler in India, she especially enjoyed her science classes because they fostered her curiosity and allowed her to ask more questions than other subjects did. She was curious about how to use science to solve the challenges she and her community faced, like access to safe drinking water. Seawater surrounded them, so could they find a way to convert it into drinking water?

As part of India’s annual National Teachers’ Day celebration, high school seniors take on the role of educators and teach their younger peers for the day. Dr. Chakrapani loved the experience, and it solidified what she already knew: She wanted to go to college to be a science teacher. After earning her bachelor’s degree, she entered back-to-back master’s programs in biochemistry and biomedical engineering, where she had the opportunity to do hands-on research.

This time of year, many creepy crawlies take center stage to frighten people of all ages. To celebrate Halloween, we've conjured up a slideshow of fascinating but spooky species that NIGMS-funded scientists study. Some of these creatures drink blood like vampires, while others—frogs, worms, flies, and salamanders—are perfect cauldron ingredients for a witch's brew. Check out the slideshow—if you dare!