Catégories : Tous - bacteria - shapes - reproduction

par Scarlett BTS Il y a 5 années

162

Prokaryotes

Prokaryotes are single-celled organisms that play a crucial role in various ecological interactions. They form biofilms, which are communities of bacteria that adhere to surfaces, exemplified by dental plaque.

Prokaryotes

Prokaryotes Scarlett Barreto

Ecological Interctions

Parasitism
parasite lives on or in another oranism or host, causing some harm.
Commensalism
association between two organism in which one benefits and the other derives neither benefit or harm
Mutualism
beneficial to both organisms involved
Symbiosis
interaction between two different organisms living in close physical association.
Biofilm
ex: plaque
bacteria in a community that covers a surface

Nutritional Categories

Metabolisim
Decomposers

decomposes organic material

Methanogens

reduces carbon dioxide to methane

Nitrogen Fixers

nitrogen is converted to ammonia

Facultative Anaerobes

makes ATP with or without oxygen

Obligate Anaerobes

Poisoned by Oxygen

Obligate Aerobes

requires oxygen to grow

Energy and Carbon Source
Photoheterotrophs

use light for energy, but not carbon dioxide as their sole carbon source

Chemoheterortrophs

obtain energy by oxidation of electron donors in their environment

Chemoautotrophs

Gets energy from the oxidation or inorganic compounds

Photoautotroph

Carry our photosynthesis

Archaea

Euyarchaeota
Korarchaeota

Thermophilic

Crenarchaeota

thermophilic or hyperthermophilic organisms

Aigarchaeota

contains microorganisms from terrestrial and subsurface geothermal ecosystems

Thaumarchaeota

embraces ammonia-oxidizing organisms from different enviroments.

Separate deep-branching phylum within archaea

Uses of Prokaryotes

Bioengineering
Bioremediation
Make Plastics
Transgenic Plants
Cloning

Lifestyles

Extremophiles
Psychrophiles

can grow in low tempratures

Alkalinophiles

survive in alkaline environments

Acidophiles

thrive under highly acidic conditions

Thermophiles

grows best at higher than normal tempratures

Halophiles

an organism that grows in or can tolerate saline conditions

Reproduction

Sexual
Transduction

carry prokaryotic genes from one host cell to another

Conjugation

DNA is transferred between two prokaryotic cells that are temporarily joined.

Horizontal Gene Transfer

movement of genes from one organism to another

Transformation

Genotype and possibly the phenotype of prokaryotic cell are altered by the uptake of foreign DNA from its surroundings.

Asexual
Binary Fission

single prokaryotic cell divides into two, then 4, and so on

Bacteria

Gram Positive Bacteria
Ex: Streptomyces (Source of many antibiotics)
include solitary species
rival the proteobacteria in diversity
Cyanobacteria
Ex: Oscillatoria
Some filaments have cells specialized for nitrogen fixation
Gram-negative photoautotrophs
Spirochetes
Ex: Leptospira
Many are free living, others are notorious pathogenic parasites
helical, gram-negative
Chlamydias
Ex: Chlamydia trachomatis
Gram negative walls
Only survive within animal cells
Proteobacteria
Epsilon

Ex: Campylobacter- causes blood poisoning

Most are pathogenic to humans or other animals

Delta

Ex: Bdellovibrios- attack other bacteria

Slime-secreting myxobacteria

Gamma

Some are pathogens (ex. Salmonella)

Includes sulfer bacteria.

Beta

Wide range of aquatic species (ex: Rubrivivax)

Nutritionally Diverse

Alpha

Associated with Eukaryotic hosts (ex: Rhizobium)

Bacterial Shapes
Spirillium

Curved or corkscrew-like spiral

Bacillus

Rod-shape

Coccus

Sperical