Prokaryotic vs. Eukaryotic Cells

All living things are made of cells, but not all cells are the same. Scientists classify cells into two main types: prokaryotic cells and eukaryotic cells. These two cell types differ in structure, complexity, and where they are found in nature.

Prokaryotic cells are simple cells found in single-celled organisms like bacteria and archaea. They do not have a nucleus. Instead, their DNA floats freely in the cytoplasm, the jelly-like material inside the cell. Prokaryotic cells also lack other membrane-bound organelles. Most have a cell wall and may have flagella or pili to help them move or stick to surfaces. Despite their simplicity, they carry out all the basic functions of life.

In contrast, eukaryotic cells are more complex. They do have a nucleus, which holds the cell’s DNA. Eukaryotic cells contain many organelles, such as mitochondria (which produce energy), endoplasmic reticulum (which builds proteins), and chloroplasts (in plant cells for photosynthesis). These cells are found in animals, plants, fungi, and protists. Many eukaryotic organisms are multicellular, and their cells can be specialized to perform specific jobs.

The biggest differences between prokaryotic and eukaryotic cells are the presence of a nucleus and organelles. Eukaryotic cells are also usually larger and can be part of complex organisms. Prokaryotic cells are smaller, but they are ancient and have adapted to live in many environments, including extreme ones.

Understanding the differences between these two cell types helps scientists learn how life evolved and how organisms function.

Fun Fact: The cells in your body are eukaryotic—but the bacteria living in your gut are prokaryotic!