What does prokaryon mean?
A prokaryon is a single-celled organism whose cell lacks a membrane-bound nucleus. Bacteria and archaea are prokaryons, making the term useful when referring broadly to organisms with this cellular organization. In a prokaryon, the genetic material is located in a region called the nucleoid, where it is not enclosed by the membrane that surrounds the nucleus of a eukaryotic cell. Prokaryons also lack the membrane-bound compartments, such as mitochondria and endoplasmic reticulum, characteristic of eukaryotic cells. Although “prokaryon” is understood and accurate, it is much less common than the standard noun “prokaryote,” which most contemporary scientific writing prefers. The adjective “prokaryotic” is correspondingly more frequent in descriptions of genes, cells, organisms, and evolutionary relationships.
nounA prokaryon is a single-celled organism whose cell lacks a membrane-bound nucleus, including bacteria and archaea. The term is a less common alternative to “prokaryote.”
- A single-celled organism, such as a bacterium or archaeon, whose cell lacks a membrane-bound nucleus.
"A prokaryon carries its genetic material in a region of the cytoplasm that is not enclosed by a nuclear membrane."
"Each prokaryon contains its genetic material in a nucleoid region rather than inside a nucleus."
"The earliest forms of life were prokaryons, and prokaryotic cells remain widespread throughout the environment."
Although this form is regular, “prokaryotes” is much more common in scientific usage.
"Prokaryons were among the earliest forms of cellular life."
Without a nucleus, a prokaryon keeps its DNA in a simpler cellular arrangement that has supported life for billions of years.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of prokaryon
The word combines Greek pro, meaning “before” or “in front of,” with karyon, meaning “nucleus.” It reflects the cellular condition in which the nuclear membrane is absent. The same Greek root appears in “karyon” and in terms such as “eukaryote,” whose prefix eu- contrasts with the prefix of a prokaryote.
Related word forms
How prokaryon is actually used
This is a valid scientific term but is uncommon in general use. “Prokaryote” is normally preferred, including in discussions of bacteria and archaea.
Easily confused with prokaryon
Both terms refer to a cell without a membrane-bound nucleus, but “prokaryote” is the standard and far more common scientific term.
A prokaryon lacks a membrane-bound nucleus, whereas a eukaryote has one.