Noun. /PRO-teen/
by Hannah Thrash
What does it mean?
A protein is a large molecule, or macromolecule, that is present within cells. They work together to promote cell survival. The protein is the final step in the central dogma of biology. DNA encodes all the rules and instructions for how a cell should function. RNA then reads those instructions and copies pieces of them in its own similar language to move the instructions out of the nucleus and into the soup-like part of the cell, known as the cytoplasm. The RNA codes for a specific protein that will have a specific job. Once the RNA is read by the cell, a new protein is created by stringing together molecules called amino acids. Proteins can be categorized in multiple ways; a common one is by their function. Some of their many roles include acting as enzymes, signaling molecules, or structural supports. Without proteins, cells can’t live!
Figure 1: Proteins have so many jobs! Some proteins are enzymes, participating in chemical reactions; some serve as cell signaling molecules, including hormones, defensive proteins (proteins of the immune system), and receptor proteins; and some function as structural or motor proteins. Created in BioRender by author, modified from Reece, J. B., & Campbell, N. A. (2011). Campbell biology. Boston: Benjamin Cummings / Pearson.
How do I use it in a sentence?
“This protein helps the cell receive signals from the surrounding areas.”
Etymology
The word “protein” comes from the French protéine. The French term itself can be traced to a Greek word, prōteîos, meaning “of the first quality” due to the fact that proteins are also the main component of animal nutrients.
History of usage
There is a bit of drama here! The term was originally introduced by a Dutch chemist, Johannes Geradus Mulder (1802-1880), who used it in two scientific articles he published in 1838. However, flash forward to the next century, and it was later discovered that the word was actually introduced to Mulder by his friend, Swedish chemist Jons Jakob Berzelius, in a letter he wrote to him earlier that year!
Related terms:
DNA, RNA, amino acids, cell signaling, macromolecule
Fields of study in which this word is commonly used:
Biology, Biochemistry, Molecular Biology
