Home » Biology » True difference between Prokaryotes and Eukaryotes

True difference between Prokaryotes and Eukaryotes


Grouping organisms into prokaryotes and eukaryotes allows us to distinguish between 2 patterns of cellular organization.  Bacteria and archae make up the prokaryotes (Pro-karytoes = before nucleus). While cells with a membrane bound nucleus and organelles make up the eukaryotes.  Eukaryotes include plants, animals, and blue-green algae.

 Prokaryotes Vs Eukaryotes

More Differences between Prokaryotes and Eukaryotes

Although the presence or absence of a membrane bound nucleus is the major criteria separating prokaryotes from eukaryotes, other characteristics such as size and the presence of organelles differentiate the 2 major patterns of cellular organization.


Prokaryotes (bacteria) are much smaller than eukaryotic cells. Since bacteria are much smaller than eukaryotes it is common to see bacteria living in or on eukaryotic organisms.


Organelles are compartmentalized workhorses of eukaryotic cells that allow them to produce energy, make proteins, and synthesize many other cellular components.  Prokaryotes may have ribosomes (make proteins), but they do not have many organelles that carry out more complex tasks. For example eukaryotes use mitochondria to make ATP(cellular energy) while bacteria must rely on their cell membrane to produce ATP.


Amoeba image by Josh Grosse courtesy of CDC

It is generally observed that prokaryotes are unicellular while eukaryotes are multicellular organisms. However there are exceptions  to this general observation. For example the “brain eating” amoebae, N. fowleri, is an exception to the rule because it is a unicellular eukaryotes. So despite many observed difference like size and cellularity,  the presence or absence of membrane bound nucleus and organelles are the true separator.


A Simple Summary of what you read

  • This 2 tier grouping of all organisms has been accepted as early as the 1940’s to divide organisms into groups based on cellular organization.
  • Prokaryotes do not have a membrane bound nucleus or membrane bound organelles.
  • Eukaryotes have a membrane bound nucleus and organelles which compartmentalize many functions.
  • Eukaryotes and prokaryotes generally differ in cell size and cellularity. Eukaryotes are usually larger and multicellular.
  • Prokaryotes are normally smaller than eukaryotes, and unicellular.

Check Also

blue strawberry

Can Synesthesia Reveal We Dont See The Same Colors

Have you glared at the sunset in the horizon wondering if the blue sky you …


  1. I am so grateful for the way you provided to learn TCA and Glycolysis cycle with such ease!
    I love chemsitry but had to suddenly take up bio as a compulsory subject for a semester and hence the trouble! Please could you help me with Electron Transport System, Pentose Phosphate Pathway, Gluconeogenesis, Glycogenesis and glycogenoysis! Even though i spend alot of time learning these i simply cann’t remember this. Please mail me if you are even going to consider it. I would understand if you don’t have time!
    In need of some help…
    And sincere thank you once again…
    P.S. I recommended your site to all my friends and 1 of them just told me I am a life-saver! Such is the life of us maths students!

  2. I’m glad to hear the articles helped.

    I already have a simplified article on the electron transport system. I will see I can make some tutorials on Pentose Phosphate, Gluconeogenesis,and Glycogenesis sometime this week.

    Good luck in biology.
    p.s. I’m actually taking upper level math as a bio major right now so i completely understand.

  3. i would like to know how electron transport chain occurs in bacteria.