obsidianvault/biology/G11 Pre-AP Biology/3 Classification of Prokaryotes.md

G11 Pre-AP Biology

Classification

• Living things:
  • Archaea:
    • Archaea
  • Bacteria:
    • Bacteria
  • Eukarya:
    • When the living thing is made up of eukaryotic cells.
    • Protista
    • Fungi Plantae Animalia
• On a quiz describe shapes and such by size and DNA, eg coccus prokaryotic cells are 1-10 micrometers and have circular DNA.

Morphology

Shape	Shape	Name
O	Spheres	Coccus
--	Rod-shaped	Bacillus
~~~	Spiral shapes	Spirillum

Aggregation

Shape	Aggregation	Name	Example
OO	Two's	Diplo	Neisseria Gonorrhoeae Diplocci
oooooooooo	Chain/Line	Strepto	Streptococcus Pneumoneae
888	Clumps	Staphylo	Staphylococcus Aureus

Cell Wall Structure

Domain	Cell Wall Material
Arcahaea	Doesn't have a peptidoglycan cell wall, still has a cell wall
Bacteria	Has a peptidoglycan cell wall

Staining (Not for Archaea - Only Bacteria)

• 1884, Hans Gram used a stain (now called Gram stain) that allowed bacteria distances to be seen.
• Gram positive: Has a think peptidoglycan cell wall and stained purple (eg Streptococcus pneumoniae).
• Gram negative: has a thin peptidoglycan cell wall + extra membrane and stained pink (eg Neisseria meningitis)

Dye used	Gram stain color	Gram stain result	Cell wall protein layer thickness
Crystal violet	Purple	Gram Positive	Thick peptidoglycan
Safranin	Pink	Gram Negative	Thin peptidoglycan cell wall + extra cell membrane

Habitat

• Aerobic environments (presence of oxygen) - Both archaea and bacteria.
• Anaerobic environment (no oxygen) - Both archaea and bacteria.
• Obligate aerobes - Exclusively survives in oxygen rich environments.
• Facultative aerobes - Can survive in both.
• Obligate anaerobes - Can only survive in anaerobic environments.
• Mesophiles - Organisms that live in moderate conditions.
• Many archaea are extremophiles:
  • Thermophile - Heat loving.
  • Acidophile - Acid loving (pH).
  • Halophile - Salt loving.
  • Cell separates into 2 identical cells.

Binary Fission

Prokaryote asexual reproduction. Occurs when conditions are favorable. Steps:

1. Replicate DNA.
2. Cell grows.
3. Cell elongates.
4. Septum forms.

Conjugation

Allows prokaryotes to transfer genetic information (plasmids). Steps:

1. Cell A makes a copy of its plasmid.
2. Extends conjugation pili to cell B and passes plasmid.
3. Cell B now has cell A genetic information. "If you don't finish off all the ear infection bacteria in a short time with antibiotics and quit midway, there's a chance they receive anti-antibiotic plasmids and become a lot harder to kill." Important to finish antibiotics because of conjugation and mutation.

Endospores

Structures formed by some bacteria in extremely unfavorable conditions. Essentially goes dormant (transforms into a dry seed like structure) to survive without food or high temperature.

Prokaryotic Stuff

Feature	Function	How often
Plasmid	Extra DNA	Sometimes
Flagella	Movement	Sometimes
Capsule	Extra protective layer	Sometimes
Cell wall	Supports hape/prevents from bursting	Always
Ribosome	Makes proteins
Fimbriae	Little hairs that allow them to attach
Cell membrane	Controls what enters/leaves	Always
Conjugation pilus	Conjugation