Difference Between Bacteria and Protists


Main Difference

The main difference between Bacteria and Protists is that the Bacteria belong to kingdom monera while Protists belong to kingdom protists.

Bacteria vs. Protists

Bacteria is a microscopic organism which is prokaryotes while Protists are microscopic organisms which are eukaryotes. Bacteria are autotrophic and heterotrophic in the mode of nutrition, while Protists are photosynthetic or heterotrophic or both in the mode of nutrition. Bacteria use flagella and pili to move, whereas Protists use cilia, flagella, and pseudopodia to move. Bacteria lack mitochondria, cytoskeleton, and chloroplast while Protists have these organelles. Bacteria are found in every habitat, on the other hand, Protists are found in moist places.


Comparison Chart

The Bacteria is the microscopic organism which can live in a diverse environment.Protists are microscopic, single-celled organisms which are not plants, animal or fungi but a different group of organisms.
Mode of Locomotion
Flagella and pilliCilia, Flagella, Pseudopodia
Organelles Differences
Mitochondria, Chloroplast and Cytoskeleton, is absentMitochondria may be present. The chloroplast is present in photosynthetic protists, and Cytoskeleton is present.
Strength of Immediate-Release Tablets
Found in every habitatFound in moist habitat
Mode of Nutrition
Autotrophic, HeterotrophicPhotosynthetic, Heterotrophic, OR combination
Beneficial Uses
The fermentation process, Antibiotic production, Decomposing sewage waste, Biogas production, Use in pesticidesPart of the food chain, Use in medicinal research, Use in puddings and ice creams as carrageenan

What is Bacteria?

The Bacteria is the microscopic, single-celled organism which can live in a diverse environment. Bacteria belong to prokaryotes. Bacteria differ in lengths and shape. The length of Bacteria has mostly measured in micrometers, and their shape varies from the rod, spiral to spheres. Bacteria do not possess a nucleus, and their DNA can exist either in plasmids which is a circular piece or in nucleoid which is a twisted, thread-like mass. The bacterial cell has spherical units called ribosomes, which assembles proteins with the help of information encoded in ribosomal RNA. Two protective coverings surround the bacterial cell called cell wall, and cell membrane, and the cell wall is the outer covering, but some bacteria do not have a cell wall like mycoplasms. A capsule which is outermost protective covering in some bacteria is also part of the bacterial structure. Bacteria move through long flagella, or short pilli and pills are also play the role of genetic material transfer. Bacteria can be classified based on their shape, nature of cell wall, and distinct genetic material. Based on shape, bacteria are classified as rod-shaped called cocci, cylindrical-shaped called bacilli and spiral called spirilla. Based on cell wall composition, the bacteria are classified as the Gram-positive and Gram-negative bacteria. Most bacteria reproduce by binary fission and some by budding, multiplication of cells is through the mitosis. Change in the genetic material in a bacterial cell is by the integration of additional DNA from bacterial surrounding into bacterial genome and is called horizontal gene transfer. The horizontal gene transfer is achieved by the conjugation, transformation, and transduction.


Mycobacterium, Helicobacter pylori and Bacillus anthracis, etc

What are Protists?

Protists are microscopic and single-celled organisms, but their cells are highly organized with a nucleus and some specific organelles. Protists are not plants, animals, or fungi and are a totally different group of organisms from above mentioned three categories. Protists possess a nucleus that is responsible for their genetic transfers. Protists also have specific organelles that perform specific functions, e.g. photosynthetic protists have organelles called plastids that perform photosynthesis. Plastids of some protists differ in color and in several membranes, e.g. dinoflagellates and diatoms. Protists also possess mitochondria which generate energy for them, but there are some protists which live in anaerobic conditions and possess hydrogenosomes for energy production. Protists are of two types based upon the mood of nutrition; they are photosynthetic and heterotrophs, heterotrophs divide into two categories called phagotrophic and somatotrophs. Phagotrops surround the food by their cell bodies and swallow food. Osmotrophs get nutrients from the nearby environment by absorption. Mixotrophs are class of protists which possess plastids and also eat organisms, e.g. dinoflagellates. Protists reproduce by binary fission or multiple fission, some protists reproduce sexually but very few. Free-living protists live in watery areas.


Amoeba proteus and Paramecium Aurelia etc.

Key Differences

  1. Bacteria are microscopic organism which lives in diverse habitats while Protists are microscopic organisms which live mostly on moist places.
  2. Bacteria belong to kingdom moners, on the other hand, Protists belong to kingdom Protista.
  3. Bacteria are prokaryotes while Protists are eukaryotes.
  4. Bacteria have circular nucleus or plasmids on the other hand Protists have a membrane-bound nucleus.
  5. Bacteria lack mitochondria, chloroplasts, and cytoskeleton whereas Protists have these organelles.
  6. Bacteria have flagella and pili as locomotory organs while Protists have flagella, cilia, and pseudopodia as locomotory organs.
  7. Bacteria reproduce asexually while Protists mostly reproduce asexually, but they also reproduce sexually.


The conclusion of the above discussion is that Bacteria and Protists are both microscopic organisms but belong to different kingdoms and have their own characteristics features.

Janet White

Janet White is a writer and blogger for Difference Wiki since 2015. She has a master's degree in science and medical journalism from Boston University. Apart from work, she enjoys exercising, reading, and spending time with her friends and family. Connect with her on Twitter @Janet__White