Prokaryote
Unicellular organisms have this type of cell. Some features include:
- Not having a nucleus
- Lacks organelles, organization
- Smaller than eukaryotes
Eukaryote
Multicellular organisms have this type of cell. Some features include:
- Having a nucleus
- Having organelles
- Larger than prokaryotes
Cilium (Cilia)
Flagellum (Flagella)
Osmotic Bursting / Cytolysis / Osmotic Lysis
When the cell bursts due to an osmotic imbalance. The cell gains too much water through diffusion and ends up rupturing. Cell wall prevents this phenomenon.
Cell Wall
Pilus (Pili)
Nucleoid
Region in a prokaryote where DNA is found
Glycocalix / Capsule / Slime Layer
Biofilm
Groups of bacteria sticking together, creating slimy coatings to protect them
3 Domains of Life are…
Gram-positive
Thick cell wall:
- Thick peptidoglycan layer
- No outer membrane
- Retains color in gram staining
Gram-negative
Thin cell wall:
- Thin peptidoglycan layer
- Has an outer membrane (lipopolysaccharides)
- Does not retain color in gram staining
Gram Staining
Involves crystal violet dye, iodine solution, and ethyl alcohol or acetone.
- Crystal violet dye + iodine solution form crystal violet-iodine complex
- Ethyl alcohol or acetone dehydrates peptidoglycan layer, causing it to shrink
- In gram-positive bacteria, the violet-idoine complex cannot penetrate the shrunken peptidoglycan layer, causing it to have a purple color
- In gram-negative bacteria, the peptidoglycan layer is too thin to hold the complex crystals, causing color to be lost
Differential Staining
A technique where you use different dyes to stain different microorganisms on a slide, allowing you to differentiate between the two of them more easily
Lipopolysaccharide (LPs)
Peptidoglycan
Nucleus
Nuclear DNA
Histones
Proteins in chromatin that help give structure to chromosomes (made of DNA)
Chromatin
Histones + DNA
Nucleolus
Nuclear Membrane / Nuclear Envelope
Nucleus Pores