Difference Between Bacteria and Eukaryotes

Bacteria vs Eukaryotes

Cell is the basic functional and structural unit of organisms. Depending on the basic structure of cells, all the organisms can be classified into two basic forms; namely, prokaryotes and eukaryotes. Prokaryotes are basically unicellular organisms with simple cell structures, and they can be classified into two categories; Archea and bacteria. Unlike prokaryotes, eukaryotes have complex cellular structures with well-organized cells. Bacteria and eukaryotes have some similar structures such as plasma membrane, which encloses the cells and DNA that carries genetic information. Viruses are neither prokaryotes nor eukaryotes because they lack certain basic characteristic features of living things.


All bacteria are prokaryotes and possess all the fundamental characteristic features of them. Bacteria are widely distributed all over the world and can be found in places like deep- sea caves, volcanic rims, and deep within glaciers where no other life would exist. Bacteria have very simple cellular structures with no membrane bounded nucleus. Basically, this feature makes them different from eukaryotes.


All the eukaryotes have complex cell structures, which include plasma membrane, glycocalyx, cytoplasm, cytoskeleton, and presence of membrane bounded organelles. The membrane bounded nucleus is prominent in these cells. Due to their complexity, most of the eukaryotes cannot live in harsh environment, unlike bacteria. All the animals, plants, fungi, and protists are eukaryotes.

What is the difference between Bacteria and Eukaryotes?

• Bacteria are unicellular organisms while prokaryotes can be multicellular or unicellular.

• Bacteria were colonized and abundant for over a billion years before eukaryotes appeared in the world.

• Most bacterial cells are smaller, about 1 µm in diameter, whereas most eukaryotic cells are 10 times bigger than that.

• Single circular DNA is present in bacteria whereas, in eukaryotes, proteins and DNA are complexed to form multiple chromosomes.

• Eukaryotes have membrane bounded nuclei, while not bacteria.

• True sexual reproduction (mitosis) occurs only in eukaryotes while bacteria have asexual reproduction method of binary fission.

• Unlike eukaryotes, bacteria do not have internal compartments and internal membrane system.

• Certain bacterial cells contain simple flagella that composed of a single fiber of flagellin protein while certain eukaryotes have complex flagella and cilia of which having the structure of 9+2 arrangement of microtubules.

• Bacterial flagella are rigid and spin like propellers, whereas eukaryotic flagella have a whip-like motion rather than rotating.

• Photosynthetic bacteria have two patterns of photosynthesis while photosynthetic eukaryotes have only one pattern.

• Bacteria are chemolithotrophic, whereas eukaryotes are not.

• Protein synthesis of bacteria is initiated by formyl- methionine while that of eukaryotes is initiated by methionine.

• Introns are present in eukaryotes while they are absent in bacteria.

• Translation of bacteria begins at AUG codon, preceded by special sequences that bind the ribosome, whereas that of eukaryotes begins at AUG codon, preceded by the 5’ cap that binds the ribosome.

• In eukaryotes, mRNA undergoes modifications after transcription while, in bacteria, none of modifications occur.

• Unlike in eukaryotes, transcription and translation are coupled in bacteria.