Archaea and Bacteria Flashcards
Archaea and Bacteria are prokaryotes
No nucleus, no organelles but do have ribosomes
The cell wall of bacteria is made up of what?
Peptidoglycan
Single chromosome
2,000 genes
Cell Shapes
coccus (sphere), bacillus (rod), spirillum (spiral)
Capsule
Many bacteria contain a layer of polysaccharides to help evade immune system
Respiratory Membrane
bacterial cell respiration
Thylakoid Membrane
bacterial photosynthesis
Genetic Material
single chromosome and plasmids (circular pieces of DNA)
Reproduction
Done by binary fission when conditions are good. When conditions are bad, some can make endospore.
Mechanisms for maintaining Genetic Diversity
short generation time leads to high mutation rate
Conjugation
exchanging plasmids
Transduction
genetic exchange facilitated by a virus (bacteriophages)
Transformation
pick up of random DNA from environment
Phototroph
energy received from light, Ex: plants
Chemotroph
energy received from chemical reactions, Ex: humans
Autotroph
“producers”, can make its own food
Ex: inorganic carbon (CO2)
Heterotroph
“consumers”, eat other organisms for food
Ex: organic carbon (biomolecules)
Nitrogen Fixation
few organisms can use atmospheric nitrogen (N2)
Ex: cyanobacteria (heterocyst)
Archaea described as Extremophiles
loving extreme environment conditions
Halophile
High salinity
Thermophile
High temperatures
Domain Archaea consists of 5 phyla
Euryarchaeotes, Thaumarchaeotes, Aigarchaeotes, Crenarchaeotes, Korarchaeotes
Euryarchaeotes
Include many methanogens (intestines and
swamps), some halophiles and thermophiles
Thaumarchaeotes
Chemoautotrophic ammonia oxidizers
