Prokaryotes vs Eukaryotes – Main Differences and Comparison
Prokaryotic cells, as well as eukaryotic cells, both are two fundamental classes of cells. All organisms are formed from the basic fundamental unit of life i.e. cells. Human is a eukaryote. Human cells are eukaryotic cells. Eukaryotes having membrane-bound organelles, including the primitive nucleus. Bacteria is a prokaryote. Prokaryotes don’t have a nucleus or any other membrane-bound organelles.
Difference Between Eukaryotic Cells vs Prokaryotic Cells:
Related Posts
In this article, we are going to discuss the main differences between the eukaryotes (like Human body) and prokaryotes (like Bacteria).
| S.N. | Characteristics | Prokaryotes | Eukaryotes |
| 1. | Term Origin | ‘pro’ = pre, ‘karyon’= nucleus; Greek for “primitive nucleus” | ‘eu’ = true, ‘karyo’ = nucleus; Greek for “true nucleus” |
| 2. | Definition | Organisms made up of the cell(s) that lack a cell nucleus or any membrane-bound organelles. | Organisms made up of cells that possess a membrane-bound nucleus as well as membrane-bound organelles. |
| 3. | Major groups | Bacteria, Archaea, and Bluegreen algae. | Algae, fungi, protozoa, plants, animals. |
| 4. | Origin | Around 3.5 billion years ago. | Around 2 billion years ago. |
| 5. | Size (approximate) | 0.5-3.0 μm | >5 μm |
| 6. | Cell Type | Usually unicellular (some cyanobacteria may be multicellular) | Usually multicellular |
| 7. | Complexity | Simple organization. | Complex organization. |
| 8. | Nucleus Location | Free in the cytoplasm, attached to mesosomes. | Contained in membrane-bound structure. |
| 9. | Nuclear membrane | No nuclear membrane. | Double membrane present. |
| 10. | Nucleolus | Absent in this. | Present. |
| 11. | Chromosome number | One | More than one |
| 12. | Chromosome shape | Circular | Linear |
| 13. | Genes | Expressed in groups called operons. | Expressed individually |
| 14. | Genome | DNA haploid genome | DNA diploid genome |
| 15. | DNA base ratio (G+C %) | Near about 28-73 | about 40 |
| 16. | DNA wrapping on proteins | Multiple proteins act together to fold and condense prokaryotic DNA. Folded DNA is then organized into a variety of conformations that are supercoiled and wound around tetramers of the HU protein. | Eukaryotes wrap their DNA around proteins called histones. |
| 17. | Genome nature | Efficient and compact with little repetitive DNA. | This present with large amounts of non-coding repetitive DNA. |
| 18. | Membrane-bound organelles | Absent | Both membrane-bound and lack membrane-bound organelles present. |
| 19. | Ribosomes (sedimentation coefficient) | 70S (50S + 30S). Smaller unit present. | 80S (60S + 40S). Larger unit present. |
| 20. | Ribosome’s location | Free in the cytoplasm or bound to the cell membrane. | Attached to rough endoplasmic reticulum and also found freely in the cytoplasm. |
| 21. | Mitochondria | Absent | Present. |
| 22. | Golgi bodies | Absent | Present. |
| 23. | Endoplasmic reticulum | Absent | Present. |
| 24. | Mesosomes | Present. Performs the function of Golgi bodies and mitochondria and also help in the separation of the chromosome during cell division. | Absent |
| 25. | Lysosomes | Absent | Present |
| 26. | Peroxisomes | Absent | Present |
| 27. | Chloroplasts | Absent; chlorophyll scattered in the cytoplasm | Present (in plants) |
| 28. | Fimbriae | Prokaryotes may have pili and fimbriae (the appendage that can be found on many Gram-negative and some Gram-positive bacteria). | Absent |
| 29. | Microtubules | Absent. | Present |
| 30. | Centrosome | Absent | Present in animals cell. |
| 31. | Cytoskeleton | May be absent | Present |
| 32. | Glycocalyx | Present | Only in some |
| 33. | Cytoplasmic streaming | Absent | Present |
| 34. | Cytoplasmic membrane | Sterols absent (except Mycoplasma) | Contains sterols. |
| 35. | Cell wall | Complex hard structure made up of protein, lipids, and peptidoglycans. | Present for plant cells and fungi; otherwise absent |
| 36. | Muramic acid | Present | Absent |
| 37. | Movement | Simple flagellum, if present | Complex flagellum, if present |
| 38. | Respiration | Through cytoplasmic membrane. | By mitochondria. |
| 39. | Energy production site | Electron transport chain found in the cell membrane | Inside membrane-bound mitochondria |
| 40. | Metabolic rate | Higher due to the larger surface area to volume ratio. | Comparatively slow than a prokaryotic cell. |
| 41. | Reproduction | Only asexual (binary fission) | Both sexual and asexual reproduction present. Mitotic division |
| 42. | Generation time | Shorter | Relatively longer. |
| 43. | Genetic Recombination | Partial, unidirectional transfer | Meiosis and fusion of gametes occur. |
| 44. | Zygote | Merozygotic (partially diploid) | Diploid(2n) cell. |
| 45. | Extrachromosomal DNA | Occur in Plasmid. | Inside the mitochondria. |
| 46. | DNA replication | occurs in the cytoplasm. | Occurs in the nucleus. |
| 47. | Transcription and translation | occur simultaneously. | Transcription occurs in the nucleus and then translation occurs in the cytoplasm. |
Also Read: Cytokines- Mechanism of action and Functions