A human cell and a bacterial cell are both alive, but look inside them and you’ll discover a surprisingly different setup. One has a nucleus and a collection of specialized compartments, while the other keeps its genetic material in a less compartmentalized region.
So, what is the difference between prokaryotic and eukaryotic cells? The biggest distinction is that eukaryotic cells have a membrane-bound nucleus and other membrane-bound organelles, while prokaryotic cells do not. Prokaryotes include organisms in the domains Bacteria and Archaea, whereas eukaryotes include animals, plants, fungi, and protists.
That basic difference, however, leads to several other differences involving cell size, DNA organization, reproduction, internal structures, and how cellular activities are organized.
Let’s break it all down.
What Are Prokaryotic and Eukaryotic Cells?
Before comparing them, it helps to understand what these two terms actually mean.
Prokaryotic cells are cells that lack a membrane-bound nucleus. Their DNA is located in a region called the nucleoid rather than inside a nucleus. Prokaryotic organisms are found in the domains Bacteria and Archaea.
Eukaryotic cells, on the other hand, contain a membrane-bound nucleus that houses their genetic material. They also contain various membrane-bound organelles, such as mitochondria and the endoplasmic reticulum, that perform specialized jobs inside the cell.
In simple terms:
- Prokaryotic = no membrane-bound nucleus
- Eukaryotic = membrane-bound nucleus
- Bacteria and Archaea = prokaryotes
- Animals, plants, fungi, and protists = eukaryotes
Both types of cells are capable of carrying out the basic processes needed for life. They simply organize those processes differently.
Prokaryotic vs Eukaryotic Cells: Quick Comparison
Here’s the difference at a glance:
| Feature | Prokaryotic Cells | Eukaryotic Cells |
|---|---|---|
| Nucleus | No membrane-bound nucleus | Membrane-bound nucleus |
| DNA location | Nucleoid region | Nucleus |
| DNA structure | Usually one main circular chromosome | Usually multiple linear chromosomes |
| Membrane-bound organelles | Generally absent | Present |
| Typical size | About 0.1–5 µm | About 10–100 µm |
| Examples | Bacteria and Archaea | Animals, plants, fungi, protists |
| Cell organization | Generally simpler | Generally more compartmentalized |
| Cell division | Commonly binary fission | Mitosis; meiosis produces reproductive cells in many organisms |
| Ribosomes | Present | Present |
| Plasma membrane | Present | Present |
| Cytoplasm | Present | Present |
| Cell wall | Common among prokaryotes, but composition varies | Present in plants and fungi, absent in animal cells |
The important word in that table is generally. Biology has exceptions, so it’s better to understand these characteristics as broad patterns rather than rigid rules.
The Biggest Difference: The Nucleus
If you remember only one difference between prokaryotic and eukaryotic cells, remember the nucleus.
A eukaryotic cell has a nucleus surrounded by a membrane. This nuclear envelope separates the cell’s DNA from the surrounding cytoplasm and helps organize processes involving genetic information.
A prokaryotic cell does not have a membrane-bound nucleus.
Instead, its chromosome is concentrated in an area called the nucleoid. The DNA is therefore located within the cell but isn’t enclosed inside a nucleus.
Think of it like this:
Prokaryotic cell:
DNA → nucleoid region
Eukaryotic cell:
DNA → nucleus → surrounded by nuclear membrane
This distinction is the foundation for understanding the rest of the comparison.
Prokaryotic Cell Structure
Prokaryotic cells may be relatively simple compared with eukaryotic cells, but “simple” doesn’t mean unimportant or incapable.
A typical prokaryotic cell contains several structures essential for survival.
Cell Membrane
The plasma membrane forms a boundary between the cell and its environment. It controls what enters and leaves the cell and is found in both prokaryotic and eukaryotic cells.
Cytoplasm
The cytoplasm is the internal environment where many cellular processes occur.
Nucleoid
The nucleoid is the region where the main chromosome is located. Unlike a nucleus, it isn’t surrounded by a nuclear membrane.
Ribosomes
Prokaryotes have ribosomes, which are responsible for making proteins.
This is worth remembering because both prokaryotic and eukaryotic cells have ribosomes.
Cell Wall
Many prokaryotic cells have a cell wall outside the plasma membrane. Its composition varies between different groups.
For example, bacterial cell walls commonly contain peptidoglycan, while archaeal cell walls do not contain peptidoglycan.
Other Structures
Some prokaryotes also have structures such as:
- Capsules
- Flagella
- Pili
- Fimbriae
- Plasmids
Not every prokaryote has all of these structures.
For example, flagella can help with movement, while pili can have roles in attachment and genetic exchange. Plasmids are additional DNA molecules found in many bacteria and archaea.
Eukaryotic Cell Structure
Eukaryotic cells are generally more compartmentalized. Instead of performing all cellular activities in one relatively open interior, different processes can occur inside specialized structures called organelles.
Some important eukaryotic cell structures include:
Nucleus
The nucleus stores the cell’s genetic material and is surrounded by a nuclear envelope.
Mitochondria
Mitochondria are involved in cellular energy metabolism and are often described as the cell’s major sites of ATP production.
Endoplasmic Reticulum
The endoplasmic reticulum, or ER, is an interconnected membrane system.
The rough ER has ribosomes attached to its surface and is involved in the production and processing of proteins. The smooth ER performs several other functions, including roles in lipid metabolism.
Golgi Apparatus
The Golgi apparatus modifies, sorts, and packages certain proteins and lipids for transport within or outside the cell.
Lysosomes
Lysosomes are membrane-bound compartments containing enzymes that help break down various materials. They are especially characteristic of many animal cells.
Chloroplasts
Plant cells and many algae contain chloroplasts, which are associated with photosynthesis.
Cytoskeleton
Eukaryotic cells also have an extensive cytoskeleton, a network of protein structures that helps maintain cell shape, organize the interior, and support movement and transport within the cell.
This internal organization is one of the major features separating eukaryotic cells from prokaryotic cells.
Difference in Cell Size
Another major difference is size.
Prokaryotic cells are generally smaller than eukaryotic cells. OpenStax gives a typical diameter range of about 0.1–5.0 micrometers for prokaryotic cells, compared with roughly 10–100 micrometers for eukaryotic cells.
That doesn’t mean every prokaryote is smaller than every eukaryote. Biology doesn’t work quite that neatly. But as a general pattern, eukaryotic cells are substantially larger.
Why does size matter?
As a cell gets larger, its volume increases faster than its surface area. That creates challenges for transporting nutrients, gases, waste products, and other substances around the cell.
Eukaryotic cells address some of these challenges through extensive internal compartmentalization and specialized transport systems.
Difference in DNA Organization
The DNA of prokaryotic and eukaryotic cells is organized differently.
Prokaryotic DNA
A typical prokaryote has a main chromosome located in the nucleoid. It is commonly circular, although there are exceptions and additional DNA molecules can also occur.
Many bacteria and archaea can also contain plasmids, which are extra-chromosomal DNA molecules.
Eukaryotic DNA
Eukaryotic cells typically have multiple linear chromosomes located inside the nucleus.
The DNA is associated with proteins called histones, helping organize and compact the genetic material inside the nucleus.
So a useful shortcut is:
Prokaryotes: usually one main circular chromosome in a nucleoid.
Eukaryotes: usually multiple linear chromosomes inside a nucleus.
Again, “usually” matters because there are biological exceptions.
Membrane-Bound Organelles: Why They Matter
One of the most important answers to what is the difference between prokaryotic and eukaryotic cells involves organelles.
Prokaryotic cells generally do not have membrane-bound organelles such as mitochondria, Golgi apparatus, or endoplasmic reticulum.
Eukaryotic cells do.
This creates a major difference in cellular organization.
Imagine a large workplace where every department has its own room. One room handles accounting, another handles manufacturing, another handles shipping, and another handles management.
That’s somewhat like the compartmentalization of a eukaryotic cell.
Prokaryotic cells generally have fewer internal membrane-bound compartments, so many cellular processes occur within the cytoplasm or across the plasma membrane.
This doesn’t mean prokaryotes lack organization. They have highly coordinated molecular systems, but their internal architecture is different.
Prokaryotic and Eukaryotic Cells Have Some Important Similarities
It’s easy to focus so heavily on their differences that you forget what they have in common.
Both types of cells have several fundamental features.
Both Have a Plasma Membrane
The plasma membrane separates the cell from its environment and regulates the movement of substances.
Both Have DNA
DNA carries genetic information in both prokaryotic and eukaryotic cells.
Both Have Ribosomes
Types of cells use ribosomes to synthesize proteins.
Both Have Cytoplasm
Have an internal cellular environment in which many biochemical reactions occur.
These similarities are important because they show that prokaryotic and eukaryotic cells aren’t completely unrelated designs. They share fundamental characteristics of cellular life.
Examples of Prokaryotic Cells
The two domains containing prokaryotic organisms are:
- Bacteria
- Archaea
Bacteria are incredibly diverse and can be found in environments ranging from soil and water to the human body.
Archaea are also diverse and include organisms capable of living in environments with unusual conditions, although they are not restricted to extreme environments.
Some familiar bacterial examples include Escherichia coli (E. coli) and various species of Bacillus.
It’s important to remember that “bacteria” and “prokaryotes” aren’t exactly interchangeable terms. Archaea are also prokaryotes.
Examples of Eukaryotic Cells
Eukaryotic organisms include:
- Animals
- Plants
- Fungi
- Protists
That means the cells in your body are eukaryotic cells.
So are the cells of a tree, mushroom, and many microscopic organisms.
Interestingly, not every eukaryote is multicellular. Some eukaryotic organisms consist of a single cell, meaning eukaryotic does not automatically mean multicellular.
Prokaryotic vs Eukaryotic Reproduction
Prokaryotes and eukaryotes also differ in how their cells divide.
Many prokaryotic cells reproduce through a process called binary fission. During this process, the cell duplicates its genetic material and divides to produce daughter cells.
Eukaryotic cells use more complex processes.
Mitosis is involved in producing genetically similar daughter cells for growth, tissue maintenance, and other functions. Meiosis is used in the formation of reproductive cells in organisms that reproduce sexually.
The details vary among different organisms, but the overall processes are more compartmentalized and elaborate than typical prokaryotic cell division.
Cell Wall Differences
Cell walls are another area where the comparison gets interesting.
Many prokaryotes have cell walls, but the material making up the wall differs between Bacteria and Archaea.
Bacterial cell walls commonly contain peptidoglycan.
Archaeal cell walls do not contain peptidoglycan and can have different chemical compositions.
Among eukaryotes, cell walls are found in plants, fungi, and some other groups, but animal cells do not have cell walls.
Plant cell walls are primarily associated with cellulose, while fungal cell walls contain materials such as chitin.
So simply asking whether a cell has a cell wall isn’t enough to tell you whether it’s prokaryotic or eukaryotic.
A Simple Way to Remember the Difference
If you’re studying biology and need a quick memory trick, focus on the word “nucleus.”
Prokaryotic
Think:
Pro = before
Karyon = nucleus
A prokaryotic cell does not have a membrane-bound nucleus.
Eukaryotic
Think:
Eu = true
Karyon = nucleus
A eukaryotic cell has a membrane-bound nucleus.
Another easy memory trick is:
Prokaryotes = no nucleus. Eukaryotes = nucleus.
Once you remember that, the other differences become much easier to organize.
Why Are Prokaryotic Cells Considered Simpler?
Prokaryotic cells are generally described as simpler because they lack the extensive internal membrane-bound compartments found in eukaryotic cells.
But “simpler” should not be confused with “primitive” or “less successful.”
Prokaryotes are extraordinarily diverse and have adapted to an enormous range of environments. They can carry out sophisticated metabolic processes and play essential roles in ecosystems, nutrient cycles, agriculture, medicine, and human health.
Their relatively compact organization can also allow rapid growth and reproduction under favorable conditions.
So the difference is primarily cellular architecture, not a measure of biological importance.
Why Are Eukaryotic Cells More Compartmentalized?
Eukaryotic cells have specialized compartments that allow different biochemical processes to occur in controlled environments.
For example, genetic material is housed in the nucleus, while mitochondria have specialized roles in energy metabolism. The endoplasmic reticulum and Golgi apparatus work together in processing and transporting many cellular products.
This compartmentalization is particularly useful for larger and more complex cells.
It allows different parts of the cell to perform specialized tasks without everything happening in the same space.
Prokaryotic vs Eukaryotic Cells: Key Differences to Remember
If you’re preparing for a biology exam, focus on these eight points:
- Nucleus: Prokaryotes lack a membrane-bound nucleus; eukaryotes have one.
- Organelles: Prokaryotes generally lack membrane-bound organelles; eukaryotes have them.
- DNA location: Prokaryotic DNA is in the nucleoid; eukaryotic DNA is primarily in the nucleus.
- Chromosomes: Prokaryotes commonly have a main circular chromosome; eukaryotes typically have multiple linear chromosomes.
- Size: Prokaryotic cells are generally smaller.
- Organisms: Bacteria and Archaea are prokaryotic; animals, plants, fungi, and protists are eukaryotic.
- Cell division: Binary fission is common in prokaryotes, while eukaryotic cells use processes such as mitosis and meiosis.
- Compartmentalization: Eukaryotic cells have much more extensive internal membrane-bound compartments.
Frequently Asked Questions
What is the main difference between prokaryotic and eukaryotic cells?
The main difference is the presence of a membrane-bound nucleus. Prokaryotic cells lack one, while eukaryotic cells have one. Eukaryotic cells also contain membrane-bound organelles that are generally absent from prokaryotes.
Are bacteria prokaryotic or eukaryotic?
Bacteria are prokaryotic. They belong to one of the two domains of life made up of prokaryotic organisms, the other being Archaea.
Are humans prokaryotic or eukaryotic?
Humans are eukaryotic. Human cells have membrane-bound nuclei and various membrane-bound organelles.
Do prokaryotic cells have a nucleus?
No. Prokaryotic cells do not have a membrane-bound nucleus. Their DNA is concentrated in a region called the nucleoid.
Do prokaryotic cells have DNA?
Yes. Prokaryotic cells contain DNA, just as eukaryotic cells do. The major difference is how that DNA is organized and where it is located.
Do prokaryotic cells have mitochondria?
No. Prokaryotic cells do not contain membrane-bound mitochondria. Their energy-related processes occur through mechanisms associated with the cell membrane and other cellular components.
Do eukaryotic cells have cell walls?
Some do, but not all. Plant and fungal cells have cell walls, while animal cells do not.
Are all eukaryotic organisms multicellular?
No. Some eukaryotic organisms are single-celled. Therefore, eukaryotic refers to cellular organization, not whether an organism has one cell or many.
Which is larger, a prokaryotic or eukaryotic cell?
Eukaryotic cells are generally larger. Typical prokaryotic cells are about 0.1–5 micrometers in diameter, while eukaryotic cells are often around 10–100 micrometers.
What do prokaryotic and eukaryotic cells have in common?
Both have a plasma membrane, cytoplasm, DNA, and ribosomes. These shared structures are fundamental to cellular life.
Conclusion: What Is the Difference Between Prokaryotic and Eukaryotic Cells?
So, what is the difference between prokaryotic and eukaryotic cells?
The easiest answer is to start with the nucleus. Prokaryotic cells do not have a membrane-bound nucleus or the extensive collection of membrane-bound organelles found in eukaryotic cells. Eukaryotic cells do.
From there, the differences become easier to understand. Prokaryotes are generally smaller and less internally compartmentalized, with DNA concentrated in a nucleoid. Eukaryotes are generally larger, contain a nucleus, and organize many cellular processes inside specialized organelles.
At the same time, don’t overlook their similarities. Both have DNA, ribosomes, cytoplasm, and a plasma membrane, showing that very different cellular architectures can still perform the fundamental tasks required for life.
If you’re studying cell biology, the best next step is to learn the major cell organelles and their functions. Once you understand what each structure does, the difference between prokaryotic and eukaryotic cells becomes much easier to remember—and much easier to explain in your own words.
