Prokaryotic Cells

Of the two types of cells, Eukaryotes and Prokaryotes

Prokaryotes are the simplest.

These cells don’t have any membrane-bound organelles or a nucleus, and all of the prokaryotes are single-celled organisms.

Identifying prokaryotes

Because prokaryotes are less complex than eukaryotes, they have fewer complex functions and are therefore smaller than eukaryotic cells.

The average size of a eukaryote is from 10-100 micrometers and the average size of a prokaryote is around 1-3 micrometers.

Prokaryotes don’t have organelles, which are required for the cell to carry out very sophisticated functions.

All prokaryotes share some of the same types of features. They all have DNA, cytoplasm, ribosomes, and they have a membrane. The importance of the DNA is so that it can carry the genetic information of the cell.

Both the membrane and cytoplasm assist in making sure that the cell keeps it shape as well as in protecting it. The ribosomes assist in making proteins for the cell.

When you see the prokaryote DNA is appears completely different from the DN in eukaryotic cells. Prokaryote DNA is circular and small and kind of looks like a hula-hoop.

Prokaryotes don’t have a nucleus so their DNA freely floats around in their cytoplasm. Eukaryotic cells have a nucleus that houses their DNA.

Prokaryotic cells have cells walls in the same way that plants do and these are used as part of a protection.

Prokaryotes also produce asexually, meaning by themselves, through a process known as “binary fission,” which is a kind of very simple mitosis; or by “budding”, which is similar to the way plants bud.

Most prokaryotic cells also have a high metabolic rate and a high growth rate.

Eukaryotes are found in both multi-cellular and some singularly-celled organisms, but prokaryotes are always single-celled organisms.

How did prokaryotes Come About?

Scientists that study cells believe that the appearance of the first prokaryotes on earth was around 3.5 billion years ago.

For many years they were the only life on earth until around 1.5 billion years ago when the prokaryotes evolved into eukaryotes.

Prokaryotes have two groups: archaea and bacteria. While there are some differences between the two, both don’t have a nucleus or organelles.

Why are prokaryotes important?

Prokaryotic cells help to maintain the balance for all life on earth.

These cells play a critical part in the recycling process of nutrients from decomposing organisms.

By taking in the nutrients from dead organisms they allow the nutrients to be re-used.

Prokaryotic organisms are also involved in the metabolic processes for other organisms, such as us.

They help our immune systems, in our digestion, and are even a source for our vitamins.

Prokaryotes Facts for Kids

  • Prokaryotes are thought to be the oldest organisms on earth.
  • Prokaryotes have cytosol that looks very grainy. Its appearance is due to the ribosomes that are found throughout the cytosol.
  • Prokaryote DNA floats freely but is usually found in concentration in or around what they call the “nuclear region.”
  • A special type of prokaryotic bacteria cell called “Archaea” has been found to live on volcanic vent edges located deep in the ocean and in other parts of the world.
  • Since bacteria is a prokaryote, the National Institutes of Health have reported that these outnumber our own human cells ten-to-one.
  • Many of our scientific words come from both Greek and Latin sources. A prokaryote is Greek and is created from two words: “pro”, meaning before, and “Karyon”, meaning nut or kernel. It literally translates to “before nucleus”, which describes the fact that prokaryotic cells don’t have a nucleus.

 Interesting Facts about Biology

  • A mushroom top is called the “cap” and the little plates that are located under the cap are called the “gills.”
  • Animals that have their skeletons outside (exoskeletons), such as crabs and insects are often called arthropods.
  • While people think all carbohydrates can be somewhat unhealthy, there are some carbohydrates that help in the absorption of calcium for our bodies.
  • Although the bones in our bodies stop growing around the age of 20 years, they continue to build new bone cells throughout our lives.
  • Scientists classify our eye organ as part of our nervous system.
  • Although it’s called the “small intestine”, it is really a lot longer than our “large intestine.”

Prokaryotic Cells Quiz

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