| Criteria | Prokaryotic cell | Eukaryotic cell |
|---|---|---|
| Size | Mostly 1 to 10µm | Mostly 10 to 100µm |
| Multicellular forms | Rare | Common |
| Nucleus | Nucleoid region (No real nucleus) | Real nucleus with double membrane. |
| Cytoplasmic membrane | Cytoplasmic membrane is only unit membrane system of majority of prokaryotes. Internal compartmentalization by unit membrane system is absent. | Presence of a multiplicity of unit membrane systems within, is a characteristic property of eukaryotic cell. Many of internal unit membranes are structurally different from cytoplasmic membranes. |
| Cytoplasmic membrane of prokaryotes constitutes a much more selective barrier between cell and external environment than does membrane of eukaryote cell. | Cytoplasmic membrane of eukaryotes is less selective barrier than prokaryotic cytoplasmic membrane. | |
| In many prokaryotes cytoplasmic membrane perform a role in energy yielding metabolism. | Eukaryotic plasma membrane never perform a role in energy yielding metabolism. | |
| Exocytosis and Endocytosis | Absent. Hence it lacks biological properties that are dependent on the capacity for endocytosis. Ex. Ability to perform intracellular digestion. To harbor cellular endosymbiots. |
Observed |
| Respiration | Among aerobic bacteria, respiratory electron transport system is incorporated into cell membrane. | Machinery of respiration is incorporated into the inner membrane of mitochondrion |
| Cell membrane | Sterols are not found in significant amount in the cell membrane of prokaryote. | Cell membrane contains sterols. |
| Cell wall | Except for mycoplasma, thick cell wall is always present, which contains amino sugars and muramic acid. | Not always present, if present, contains simple substances like cellulose, mannose, xylans. |
| Cell division | Binary fission (simple division) | Mitosis and Meiosis |
| DNA | Double stranded, circular or linear | Linear, double stranded. |
| Histone | DNA never associated with histone proteins. | DNA associated with histone |
| Ribosomes | 70S type (50S+30S) | 80s type (60S+40S) |
| Protein synthesis | Starting amino acid in protein synthesis – methionine | Starting amino acid in protein synthesis – N-formylmethionine. |
| Amount of genetic information | Less by several orders of magnitude than contained in eukaryotes | Much more than prokaryotes. |
| Changes in Chromosome | During cell cycle chromosome never undergoes changes of length, thickness by coiling. | Chromosome undergoes changes of length, thickness by coiling during cell cycle. |
| Cell movement | Flagella | Flagella and cilia containing microtubules; lamellipodia and filopodia containing actin |
| Flagella | Simple in structure. | Complicated in structure, consisting of 2 central and nine peripheral double fibrils. |
| Means of reproduction | Most prokaryotes normally exist and reproduce by asexual means in the haploid state (diploid state may occur but rarely.) | Diploidy is the character of many groups of eukaryotes |
