| Prokaryotic cells | - Bacteria and archaea (ancient bacteria) |
| The structure of eukaryotic cells (in comparison to prokaryotes) | - True nucleus
- Linear DNA, no plasmids
- DNA associated with proteins, histones
- Membrane-bound organelles
- Chloroplasts in plants
- Large ribosomes
- Cell wall made of cellulose
- No capsule
- No flagellum |
| The structure of prokaryotic cells (in comparison to eukaryotes) | - No true nucleus
- Circular DNA, plasmids
- DNA not associated with proteins
- No membrane-bound organelles
- No chloroplasts, only bacterial chlorophyll
- Small ribosomes
- Cell wall made of murein
- Capsule
- Flagellum |
| Capsule function | - Protects bacterium from other cells
- Helps groups of bacteria to stick together for further protection |
| Circular DNA function | - Possesses the genetic information for replication |
| Plasmid function | - Possesses genes that may aid the survival of bacteria in adverse conditions
- Like producing enzymes that break down antibiotics |
| Flagellum | - Long and hair-like
- Rotates to make cell move |
| Viruses | - Acellular, non-living particles
- Smaller than bacteria |
| Structure of viruses | - Contains DNA + RNA
- Can only multiply in living cells
- The nucleic acid is enclosed in a protein coat, capsid
- Some viruses surrounded by lipid envelope |
| Importance of capsid or lipid envelope | - They have attachment proteins
- Which identifies and attaches to host cells |
