Figure: Eukaryotic cell differ from a prokaryotic cell in appearance
Detailed Difference between Prokaryotic Cell and Eukaryotic Cell
Understanding the differences between prokaryotic and eukaryotic cells is vital in the field of biology. Class 9 and Class 11 students often explore these distinctions to gain a comprehensive understanding about difference between Prokaryotes and Eukaryotes. A detailed comparison between prokaryotic and eukaryotic cell types is presented in the table below, which outlines 30 key differences between them. Prokaryotic cells lack a true nucleus and membrane-bound organelles, while eukaryotic cells possess a well-defined nucleus and various organelles. Additionally, prokaryotic cells have a simpler structure and a cell wall primarily composed of peptidoglycan. Eukaryotic cells, on the other hand, are larger, more complex, and have diverse membrane-bound organelles. The table below provides a comprehensive overview of the many dissimilarities between prokaryotic and eukaryotic cell types, shedding light on their structural and functional disparities.
Table: Difference Between Prokaryotic and Eukaryotic Cell
| Serial Number | Prokaryotic Cell | Eukaryotic Cell |
| 1 | No nucleus | True nucleus |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack a nucleus and their genetic material floats freely in the cytoplasm. | Eukaryotic cells have a true nucleus, which houses the genetic material within a nuclear membrane. |
| 2 | Circular DNA | Linear DNA |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells have circular DNA molecules that lack histones and form a single chromosome called the nucleoid. | Eukaryotic cells contain linear DNA molecules that are tightly wrapped around histone proteins, forming multiple chromosomes. |
| 3 | No membrane-bound organelles | Membrane-bound organelles |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack membrane-bound organelles and have simpler internal structures. | Eukaryotic cells possess various membrane-bound organelles, such as mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosomes, each performing specific functions within the cell. |
| 4 | Ribosomes are smaller (70S) | Ribosomes are larger (80S) |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells have smaller ribosomes, measuring 70S (made up of 50S and 30S subunits), which are involved in protein synthesis. | Eukaryotic cells have larger ribosomes, measuring 80S (made up of 60S and 40S subunits), involved in protein synthesis and are more complex in structure. |
| 5 | No membrane-bound nucleus | Membrane-bound nucleus |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack a membrane-bound nucleus and their genetic material is not separated from the cytoplasm. | Eukaryotic cells have a distinct membrane-bound nucleus that houses the genetic material, separating it from the cytoplasm. |
| 6 | No cytoskeleton | Cytoskeleton present |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack a cytoskeleton, a network of protein filaments that provide structural support, shape, and help in cell movement. | Eukaryotic cells have a cytoskeleton consisting of microtubules, microfilaments, and intermediate filaments, providing structural support, facilitating cell division, and aiding in intracellular transport. |
| 7 | Peptidoglycan cell wall (in bacteria) | Cell wall composition varies |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Many prokaryotic cells, particularly bacteria, have a peptidoglycan cell wall that provides structural support and protection. | Eukaryotic cells have a cell wall in certain organisms, such as plants (composed of cellulose), fungi (composed of chitin), or algae (composed of various materials). The cell wall composition varies among eukaryotes. |
| 8 | Single circular chromosome | Multiple linear chromosomes |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells typically have a single circular chromosome carrying the genetic material. | Eukaryotic cells have multiple linear chromosomes, each containing a portion of the genetic material. |
| 9 | No splicing of mRNA | Splicing of mRNA occurs |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | In prokaryotic cells, mRNA is transcribed directly from DNA without introns, and it does not undergo splicing. | Eukaryotic cells have pre-mRNA molecules that undergo splicing, removing introns and joining exons before being translated into functional mRNA. |
| 10 | No membrane-bound nucleoli | Membrane-bound nucleoli present |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack membrane-bound nucleoli, the sites of ribosome synthesis. | Eukaryotic cells have membrane-bound nucleoli within the nucleus, where ribosomes are assembled. |
| 11 | Plasmids are common | Plasmids are rare |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells commonly contain plasmids, small circular DNA molecules separate from the main chromosome, which may carry additional genetic information. | Eukaryotic cells rarely contain plasmids, and if present, they are typically found in organelles like mitochondria or chloroplasts. |
| 12 | No membrane-bound mitochondria | Membrane-bound mitochondria present |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack membrane-bound mitochondria and generate energy through simpler mechanisms, such as the plasma membrane. | Eukaryotic cells possess membrane-bound mitochondria, where cellular respiration takes place, producing energy in the form of ATP. |
| 13 | No introns in genes | Genes contain introns and exons |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Genes in prokaryotic cells lack introns and are typically composed of continuous coding sequences. | Eukaryotic cells have genes that contain both introns and exons. Introns are non-coding regions that are transcribed into pre-mRNA but are spliced out during mRNA processing, while exons are the coding regions that are translated into proteins. |
| 14 | No membrane-bound organelles involved in endocytosis | Membrane-bound organelles involved in endocytosis |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells do not possess membrane-bound organelles specifically dedicated to endocytosis, the process of engulfing and internalizing external materials. | Eukaryotic cells have specialized membrane-bound organelles, such as endosomes and lysosomes, involved in endocytosis, allowing for the internalization and processing of extracellular materials. |
| 15 | Binary fission | Mitosis or meiosis |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells reproduce through binary fission, a simple process of dividing into two equal daughter cells. (see diagram below) | Eukaryotic cells undergo mitosis (in somatic cells) or meiosis (in reproductive cells) for cell division, involving intricate steps such as chromosome duplication, alignment, and separation. (see diagram below) |
| 16 | No membrane-bound cytoplasmic compartments | Membrane-bound cytoplasmic compartments exist |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack membrane-bound compartments within the cytoplasm, such as the endoplasmic reticulum and Golgi apparatus. | Eukaryotic cells possess membrane-bound compartments that facilitate compartmentalization and specialization of cellular functions, including the endoplasmic reticulum, Golgi apparatus, and vesicles. |
| 17 | No nuclear envelope | Nuclear envelope present |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack a nuclear envelope or membrane surrounding the genetic material. | Eukaryotic cells have a distinct nuclear envelope that separates the nucleus from the cytoplasm, consisting of inner and outer membranes with nuclear pores for selective transport of molecules. |
| 18 | No mitotic spindle | Mitotic spindle formation during cell division |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells do not form a mitotic spindle during cell division. | Eukaryotic cells form a complex mitotic spindle, consisting of microtubules and associated proteins, to separate chromosomes during cell division. |
| 19 | No cilia or flagella | Presence of cilia or flagella |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells do not possess cilia or flagella for cellular locomotion. | Some eukaryotic cells have cilia or flagella, which are whip-like appendages involved in cell movement or the movement of extracellular substances. |
| 20 | No histones associated with DNA | DNA wrapped around histone proteins |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack histones, proteins that help package and organize DNA. | Eukaryotic cells have DNA wrapped around histone proteins, forming nucleosomes, which provide structural support and regulate gene expression. |
| 21 | No complex membrane trafficking system | Complex membrane trafficking system present |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack the elaborate membrane trafficking system seen in eukaryotic cells, which involves processes like endocytosis, exocytosis, and vesicular transport. | Eukaryotic cells possess a complex membrane trafficking system that facilitates the movement of materials between different compartments, as well as interactions with the extracellular environment. |
| 22 | No peroxisomes | Presence of peroxisomes |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells do not contain peroxisomes, organelles involved in various metabolic processes, including detoxification and fatty acid oxidation. | Eukaryotic cells have peroxisomes that perform essential functions such as lipid metabolism and hydrogen peroxide breakdown. |
| 23 | No lysosomes | Presence of lysosomes |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack lysosomes, which are involved in intracellular digestion and waste management. | Eukaryotic cells contain lysosomes that function in the breakdown of macromolecules and cellular waste through hydrolytic enzymes. |
| 24 | Smaller overall cell size | Larger overall cell size |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells are generally smaller and simpler in structure compared to eukaryotic cells. | Eukaryotic cells are larger and more complex, often containing various organelles and exhibiting greater cellular diversity. |
| 25 | No nucleoli | Nucleoli present |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack distinct membrane-bound nucleoli. Instead, ribosomal RNA synthesis occurs in the nucleoid region. | Eukaryotic cells have nucleoli, which are membrane-bound structures within the nucleus involved in the production and assembly of ribosomes. |
| 26 | No endoplasmic reticulum (ER) | Presence of endoplasmic reticulum (ER) |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack an endoplasmic reticulum, a complex network of membranous structures involved in protein synthesis, lipid metabolism, and calcium storage. | Eukaryotic cells have an extensive endoplasmic reticulum that plays crucial roles in protein synthesis, lipid synthesis, and transportation of molecules within the cell. |
| 27 | No mitochondria | Presence of mitochondria |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack membrane-bound mitochondria, the powerhouse of the cell involved in energy production through cellular respiration. | Eukaryotic cells possess mitochondria, which generate ATP through aerobic respiration and play vital roles in cellular metabolism and signaling pathways. |
| 28 | No organelles involved in photosynthesis | Presence of chloroplasts for photosynthesis |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack specialized organelles, such as chloroplasts, for photosynthesis. | Eukaryotic cells in plants and algae contain chloroplasts, organelles that use light energy to synthesize glucose during photosynthesis. |
| 29 | No specialized cell junctions | Presence of various cell junctions |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells lack specialized cell junctions like tight junctions, adherens junctions, or gap junctions, which mediate cell-cell adhesion, communication, and tissue organization. | Eukaryotic cells possess various types of cell junctions that play important roles in cell adhesion, tissue integrity, and cellular communication. |
| 30 | No presence of nucleosomes | DNA organized into nucleosomes |
| Explanation of the above point of difference between Prokaryotic and Eukaryotic Cell | Prokaryotic cells do not have nucleosomes, which are DNA wrapped around histone proteins, providing structural stability and regulating gene expression. | Eukaryotic cells package DNA into nucleosomes, forming chromatin, to compact and organize the genetic material within the nucleus. |
Figure: Difference between Cell division of prokaryotes and Eukaryotes (Image source: domdomegg, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
Structural Differences Between Prokaryotic and Eukaryotic Cell:
- Nucleus: Prokaryotic cells lack a true nucleus, while eukaryotic cells have a well-defined nucleus that houses the genetic material.
- Size and Complexity: Prokaryotic cells are generally smaller and simpler in structure compared to eukaryotic cells, which are larger and more complex.
- Membrane-Bound Organelles: Prokaryotic cells lack membrane-bound organelles, such as mitochondria, endoplasmic reticulum, and Golgi apparatus, which are present in eukaryotic cells.
- Genetic Material: In prokaryotic cells, the genetic material is present as a single, circular DNA molecule located in the cytoplasm, known as the nucleoid region. Eukaryotic cells have multiple linear DNA molecules tightly organized into chromosomes within the nucleus.
- Cell Division: Prokaryotic cells undergo binary fission to divide, where the DNA replicates and the cell splits into two identical daughter cells. Eukaryotic cells undergo mitosis or meiosis, involving complex processes of chromosome replication, segregation, and cell division.
- Cell Wall: Many prokaryotic cells have a cell wall composed of peptidoglycan, a complex polymer. Eukaryotic cells may have a cell wall, but its composition differs significantly. Plant cells have a cell wall composed of cellulose, while animal cells lack a cell wall.
- Flagella: The structure and function of flagella differ between prokaryotic and eukaryotic cells. Prokaryotic flagella are simpler and composed of a protein called flagellin, while eukaryotic flagella are more complex and contain microtubules.
- Ribosomes: Prokaryotic ribosomes are smaller in size (70S) compared to eukaryotic ribosomes (80S). Additionally, the ribosomal RNA sequences differ between prokaryotes and eukaryotes.
- Cytoplasmic Organization: Prokaryotic cells have a simpler and less organized cytoplasm compared to eukaryotic cells, which have various membrane-bound compartments and organelles.
- Endomembrane System: Eukaryotic cells have an elaborate endomembrane system, including the endoplasmic reticulum, Golgi apparatus, and vesicles, involved in protein synthesis, modification, and transport. Prokaryotic cells lack this extensive endomembrane system.
These structural differences distinguish prokaryotic and eukaryotic cells and reflect their distinct biological properties and evolutionary adaptations.
Functional Differences Between Prokaryotic and Eukaryotic Cell:
- Nucleus: Prokaryotic cells lack a true nucleus, while eukaryotic cells have a well-defined nucleus that contains the genetic material.
- Organelles: Eukaryotic cells contain membrane-bound organelles, such as mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosomes, which are involved in various cellular processes. Prokaryotic cells lack these membrane-bound organelles.
- Genetic Material: Prokaryotic cells have a single circular chromosome located in the nucleoid region. Eukaryotic cells have multiple linear chromosomes that are contained within the nucleus.
- Cell Size: Prokaryotic cells are generally smaller and have a simpler structure compared to eukaryotic cells, which are larger and more complex.
- Reproduction: Prokaryotic cells reproduce through binary fission, a process where the cell divides into two identical daughter cells. Eukaryotic cells undergo mitosis (for somatic cells) or meiosis (for reproductive cells) during reproduction.
- Cell Division: Prokaryotic cell division is relatively simple and occurs rapidly. Eukaryotic cell division involves complex processes, including the formation of a spindle apparatus and the segregation of chromosomes.
- Membrane-bound Structures: Eukaryotic cells have membrane-bound structures, such as the endoplasmic reticulum and Golgi apparatus, which are involved in the synthesis, modification, and transport of proteins. Prokaryotic cells lack these elaborate membrane systems.
- Metabolism: Prokaryotic cells exhibit diverse metabolic capabilities, including anaerobic and aerobic respiration, fermentation, and photosynthesis. Eukaryotic cells have specialized organelles, such as mitochondria and chloroplasts, for specific metabolic functions.
- Cell Communication: Eukaryotic cells have more elaborate cell signaling mechanisms, including complex signaling pathways and intercellular communication, enabling coordination and regulation of various cellular processes. Prokaryotic cells have simpler communication systems.
- Complexity and Specialization: Eukaryotic cells exhibit higher complexity and specialization, with different cell types performing specific functions within multicellular organisms. Prokaryotic cells are generally less specialized.
These functional differences highlight the diverse capabilities and complexity of eukaryotic cells compared to prokaryotic cells.
References:
Vellai, Tibor, and Gabor Vida. “The origin of eukaryotes: the difference between prokaryotic and eukaryotic cells.” Proceedings of the Royal Society of London. Series B: Biological Sciences 266, no. 1428 (1999): 1571-1577.
Carrascosa, J.L., Llorca, O. and Valpuesta, J.M., 2001. Structural comparison of prokaryotic and eukaryotic chaperonins. Micron, 32(1), pp.43-50.
Bendich, A.J. and Drlica, K., 2000. Prokaryotic and eukaryotic chromosomes: what’s the difference?. Bioessays, 22(5), pp.481-486.
Qi, W., Baldwin, S.A., Muench, S.P. and Baker, A., 2016. Pi sensing and signalling: from prokaryotic to eukaryotic cells. Biochemical Society Transactions, 44(3), pp.766-773.
Murray, A.W. and Szostak, J.W., 1985. Chromosome segregation in mitosis and meiosis. Annual review of cell biology, 1(1), pp.289-315.
Cabeen, M.T. and Jacobs-Wagner, C., 2005. Bacterial cell shape. Nature Reviews Microbiology, 3(8), pp.601-610.
Egan, A.J. and Vollmer, W., 2013. The physiology of bacterial cell division. Annals of the New York Academy of Sciences, 1277(1), pp.8-28.
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