Terminology for Midterm Practial PROKARYOTES

domain Archaea

prokaryotic and often inhabit, but are not restricted to, extreme and stressful environments; extremophiles

domain Bacteria

prokaryotic and most abundant organisms on Earth

unicellular

single celled

no membrane bound organelles

no chloroplasts, mitochondria, etc.

plasma membrane

sheath around cytoplasm that regulates entrance and exit of molecules

cell wall

covering that supports, shapes, and protects cell

pilli

hairlike bristles that allow adhesion to the surfaces

flagella

rotating filament present in some bacteria that pushes the cell forward

shapes

• bacillus (rod shaped)

• coccus (spherical)

• spirillum (spiral)

colony shapes

binary fission

reproduce asexually; cell’s DNA replicates and the cell pinches in half without the nuclear and chromosomal events associated with mitosis

heterotrophic

derive energy from organic molecules made by other organisms

autotrophic

derive energy from photosynthesis or oxidation of inorganic molecules

decomposers

feed on dead organic matter and release nutrients locked in dead tissue

pathogenic

capable of causing disease or illness

commensal

an organism that lives in a close relationship with another species, where it benefits (by getting food, shelter, or transport) while the other species (the host) is neither helped nor harmed

mutualistic

relationship between two or more different species where every species gains a net benefit

nitrogen fixation

transform atmospheric nitrogen into other nitrogenous compounds that can be used as nutrients by plants

cyanobacteria

• chlorophyll

• sheath

• nitrogen fixation (provide Ammonia)

• photosynthesis

gram staining

Gram-positive has thick peptidoglycan cell walls that can retain purple dye. Gram-negative has thin cell walls that can’t retain purple dye.