Prokaryotic Cell — Definition & Examples

Eukaryotic Cells vs. Prokaryotic Cells

(Video) Prokaryotic vs. Eukaryotic Cells

by Amoeba Sisters

This video explains some of the key differences between prokaryotes (like bacteria and archaea) and eukaryotes.

What Is a Prokaryote?

Prokaryotes are single-celled organisms that do not have a true nucleus. Their internal structures are not bound by membranes. Archaea and bacteria are both types of prokaryotic cells. This might creep you out a little, but your body contains a lot of these little guys. In fact, the number of bacterial cells and human cells in you are almost equal. Now that's pretty neat.

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$\color{#8925AE}{\text{Cell}}$ : The simplest form of life and the basic unit of structure and function

$\color{#8925AE}{\text{Eukaryote}}$ : Cells that contain a nucleus and membrane-bound organelles

$\color{#8925AE}{\text{Prokaryote}}$ : Cells that do not contain a nucleus or membrane-bound organelles

What Are Prokaryotes?

Prokaryotes are organisms made from a prokaryotic cell. Let's look at three main structural characteristics they have (or lack) that distinguish them from eukaryotes:

Cells that aren't prokaryotic are called eukaryotic.

Types of Prokaryotes

Now, let's talk a little about what types of organisms are made from prokaryotic cells.

Finally, here are some defining behaviors of prokaryotic cells:

• They are unicellular

• They tend to be smaller than eukaryotic cells

• They can reproduce asexually (usually with binary fission)

• They usually have a cell wall surrounding their cell membrane

How Is a Prokaryote Different from a Eukaryote?

Just like with eukaryotic cells, there are a few distinguishing characteristics of prokaryotic cells:

• Prokaryotic DNA is free-floating in prokaryotic cells and is not contained within a membrane-bound nucleus. Their genetic material is also not bound to any proteins. Instead of being composed of multiple linear chromosomes, their DNA is made up of circular rings called plasmids.

• Prokaryotic cells lack a distinct nucleus and have no membrane-enclosed organelles.

• Protein production happens directly in the cytoplasm with free-floating ribosomes. This is different from eukaryotes, where protein production sometimes occurs on the rough ER.

• Prokaryotic cells tend to be smaller (around one to five micrometers) compared to eukaryotes (around ten to 100 micrometers).

There are several other differences between the two cell types, but these are the primary differences that you will observe.