Every life organism falls into one of two groups: standard scale or prokaryotes. Cellular structure determines which group an organism belongs to. In this article, we will explain in detail what prokaryotes and eukaryotes are and outline the differences between the two.

Prokaryote definition

Prokaryotes room unicellular organisms that lack membrane-bound structures, the many noteworthy of i beg your pardon is the nucleus. Prokaryotes cells often tend to be small, an easy cells, measuring around 0.1-5 μm in diameter.


While prokaryotic cells perform not have membrane-bound structures, they do have distinct cellular regions. In prokaryotic cells, DNA bundles together in a an ar called the nucleoid.

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Prokaryotic cell features

Here is a failure of what you might find in a prokaryotes bacterial cell.

A main region the the cabinet that consists of its DNA. Ribosome: Ribosomes space responsible because that protein synthesis. Cell wall: The cell wall surface provides structure and also protection indigenous the external environment. Most bacteria have a strict cell wall surface made indigenous carbohydrates and also proteins referred to as peptidoglycans. Cell membrane: Every prokaryote has a cabinet membrane, also known as the plasma membrane, the separates the cell from the external environment. Capsule: part bacteria have actually a class of carbohydrates that surrounds the cell wall surface called the capsule. The capsule help the bacterium attach to surfaces. Fimbriae: Fimbriae room thin, hair-like structures that help with to move attachment. Pili: Pili space rod-shaped structures connected in lot of roles, consisting of attachment and also DNA transfer. Flagella: Flagella space thin, tail-like frameworks that help in movement.

Examples the prokaryotes

Bacteria and also archaea are the two species of prokaryotes.

Do prokaryotes have actually mitochondria?

No, prokaryotes carry out not have mitochondria. Mitochondria room only uncovered in eukaryotic bio cells. This is additionally true of other membrane-bound structures choose the nucleus and the Golgi device (more on this later).One theory for eukaryotic advancement hypothesizes the mitochondria were first prokaryotic cell that lived inside various other cells. Over time, development led to these separate organisms functioning as a single organism in the form of a eukaryote.

Eukaryote definition

Eukaryotes are organisms who cells have a nucleus and also other organelles fastened by a plasma membrane. Organelles are inner structures responsible for a selection of functions, together as power production and protein synthesis.


The key structures current in a eukaryotic bio cell.

Eukaryotic cells are large (around 10-100 μm) and complex. While many eukaryotes are multicellular organisms, there space some single-cell eukaryotes.

Eukaryotic cabinet features

Within a eukaryotic cell, every membrane-bound framework carries out certain cellular functions. Below is an overview of countless of the primary components of eukaryotic cells.

The nucleus stores the hereditary information in dyed form. Nucleolus: found inside of the nucleus, the nucleolus is the part of eukaryotic bio cells where ribosomal RNA is produced.Plasma membrane: The plasma membrane is a phospholipid double layer that surrounding the whole cell and encompasses the oribel within.Cytoskeleton or cabinet wall: The cytoskeleton or cell wall provides structure, permits for cabinet movement, and plays a function in cabinet division. Ribosomes: Ribosomes are responsible for protein synthesis. Mitochondria: Mitochondria, likewise known together the powerhouses of the cell, room responsible for power production.Cytoplasm: The cytoplasm is the an ar of the cell in between the atom envelope and also plasma membrane. Cytosol: Cytosol is a gel-like substance within the cell that consists of the organelles. Endoplasmic reticulum: The absorbent reticulum is one organelle devoted to protein maturation and also transportation. Vesicles and vacuoles: Vesicles and also vacuoles are membrane-bound sacs connected in transportation and storage.

Other common organelles uncovered in many, however not all, eukaryotes incorporate the Golgi apparatus, chloroplasts and also lysosomes.

Examples the eukaryotes

Animals, plants, fungi, algae and also protozoans room all eukaryotes.

Comparing prokaryotes and also eukaryotes

All life top top Earth is composed of either eukaryotic cells or prokaryotes cells. Prokaryotes were the very first form of life. Scientists think that eukaryotes developed from prokaryotes around 2.7 billion years ago.The primary distinction between these two types of biology is that eukaryotic bio cells have actually a membrane-bound nucleus and also prokaryotic cells perform not. The nucleus is wherein eukaryotes save their genetic information. In prokaryotes, DNA is bundled together in the new closed region, yet it is not stored in ~ a membrane-bound nucleus.The nucleus is only one of plenty of membrane-bound oribel in eukaryotes. Prokaryotes, ~ above the other hand, have actually no membrane-bound organelles. Another important difference is the DNA structure. Eukaryotic bio DNA is composed of multiple molecule of double-stranded linear DNA, while the of prokaryotes is double-stranded and circular.

Key similarities in between prokaryotes and also eukaryotes


A comparison mirroring the shared and unique functions of prokaryotes and also eukaryotes

All cells, whether prokaryotic or eukaryotic, re-publishing these four features:

1. DNA

2. Plasma membrane

3. Cytoplasm

4. Ribosomes

Transcription and also translation in prokaryotes vs eukaryotes

In prokaryotes cells, transcription and also translation space coupled, definition translation starts during mRNA synthesis.In eukaryotic bio cells, transcription and also translation are not coupled. Warrior occurs in the nucleus, producing mRNA. The mRNA then exits the nucleus, and also translation wake up in the cell cytoplasm.

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What space the an essential differences in between prokaryotes and eukaryotes?

Prokaryotes and also eukaryotes vary in several important ways - these differences include structure variation - even if it is a nucleus is current or absent, and also whether the cell has membrane-bound organelles, and also molecular variation, including whether the DNA is in a one or linear form. The distinctions are summarized in the table below.
Membrane-bound organellesAbsentPresent
Cell structureUnicellularMostly multicellular; some unicellular
Cell sizeSmaller (0.1-5 μm)Larger (10-100 μm)
ComplexitySimplerMore complex
DNA FormCircularLinear
ExamplesBacteria, archaeaAnimals, plants, fungi, protists