Prokaryotes Flashcards
What two domains of life are Prokaryotes in?
bacteria and archaea
How old are prokaryotes?
~ 3500 mya
Are prokaryotes uni or multicellular?
unicellular
Do prokaryotes have a nuclear envelope?
no
Archaea was discovered in the
1970s
Archaea are derived from
bacteria
eukaryotes are derived from
archaea
When did the divergence between eukaryotes and archaea occur
1850 ma
Describe transformation
genetic alteration of a cell resulting from the direct uptake and expression of DNA
What is a unique characteristic of bacterial cell walls
contains peptidoglycan
Gram negative bacteria have what
an outer membrane
Define Fimbriae
short, bristle like structures that adhere to host
Define Pili
long, bristle like structures present singly or in pairs for DNA transfer
Fimbriae and pili are present mostly in what kind of bacteria?
Gram negative
Spirochetes are characterized by what?
Axial filamentous flagellal l(spiral shape)
What mode of nutrition do spirochetes utilize?
chemoheterotrophic
Spirochetes live how?
anaerobic and free living, some pathogens like syphillus
Spirochetes live how?
anaerobic and free living, some pathogens like syphilis and lyme disease
do hyperthermophilic and hadobacteria form a monophyletic group
no
What does Actinobacteria look like?
Filamentous spaghetti like bacteria that resemble fungi
Do all actinobacteria have a high GC content?
no
Describe characteristics of actinobacteria
Mostly aerobic, important decomposers, generally not spore forming (except for Streptomyces), some pathogenic
Describe Firmicutes (bacteria group)
rod shaped gram positive bacteria, many form spores, some are pathogenic, some are nitrogen fixing.
What are mycoplasmas?
a species of Firmicutes that are obligate parasites and have no cell wall
What is unique about Cyanobactceria?
Blue green bacteria that are responsible for origin of chloroplasts and the ONLY group to evolve oxygenic photosynthesis.
What is unique about Cyanobacteria?
Diverse blue-green bacteria that are responsible for origin of chloroplasts and the ONLY group to evolve oxygenic photosynthesis. Relatively large, and live in both aquatic environments and on land. All have chlorophyll a. Some can fix Nitrogen.
Describe Chlamydias
Very tiny bacteria that lives ONLY has intracellular parasites. Gram negative. Sensitive to penicillin. Common human STD.
Describe Proteobacteria
Photosynthetic, anaerobic bacteria. NO oxygen. Some are pathogenic. Instead of chlorophyll a, they use bacteriochlorophylls.
