Classification and microbial diversity Flashcards
Purposes of a classification system
- Organization
- Communication
- Different languages/contexts/names
Carl Woese
Proposed using 16s rRNA gene as a molecular tool, discovered domain of archea by analyzing organisms at a cellular level, started molecular phylogenies
Characteristics of Bacillus
Rod shape, gram positive, endospore production, ubiquitous, consist of 3 species that some microbiologists argue are 3 strains of one species
3 domains of life
- Archea
- Eukarya
- bacteria
Ribosomes in eukaryotes vs prokaryotes
Eukaryotes have bigger ribosomes and 18s gene, prokaryotes have 16s gene
Monophyletic
Common ancestor+all descendants
Paraphyletic
Ancestor+some of its descendants
Polyphyletic
No ancestral evolutionary relationship(convergent/analogous)
Characteristics of all living things
- replication
- cell membrane
- DNA to RNA to Protein/Dogma
- Basic metabolism
Endospores
Type of specialized cell that is produced by certain genuses of bacteria. They are dormant, highly resistant, and have protection from extreme temps, uv rays, and alcohol. They are created during hard times
Avirulent vs virulent
Avirulent= not harmful
Virulent=harmful
Candidate phyla
Phyla that cant be grown in lab
What are fungi cell walls made of?
chitin
What do all prokaryotes have?
Ribosomes, nucleoid/genetic material, cell membrane
Nuclear envelope, membrane enclosed organelles, peptidoglycan in cell wall and membrane lipids in bacteria
Nuclear enveloped: absent
Membrane enclosed organelles: some prokaryotes have them, some dont
Peptidoglycan present in cell wall
Membrane lipids: unbranched hydrocarbons
Nuclear envelope, membrane enclosed organelles, peptidoglycan in cell wall and membrane lipids in archea
Nuclear envelope: Absent
Membrane enclosed organelles: some have them some dont
No Peptidoglycan in cell wall
Membrane lipids: Some branched hydrocarbons
Nuclear envelope, membrane enclosed organelles, peptidoglycan in cell wall and membrane lipids in eukarya
Nuclear envelope: Present
Membrane enclosed organelles: Present
No peptidoglycan in cell wall
Membrane lipids: unbranched hydrocarbons
Fimbriae
Little hairs on prokaryotic cells used to move around/stick
Circular chromosomes and growth at temps>100C in archea, bacteria and eukarya
Circular chromosome: present in bacteria, present in archea and absent in eukarya
Growth at temps>100C: Some bacteria, some archea, no eukarya
Photoautotropth energy source, carbon source and types of organisms
Energy source: light
carbon source: CO2, HCO3-, or related compound
Types of organisms: Photosynthetic prokaryotes and plants(eukaryotes)
Chemoautotroph energy source, carbon source and types of organisms
Energy source: Inorganic chemicals
Carbon source: CO2, HCO3-, or related compound
Types of organisms: Unique to certain prokaryotes
Photoheterotroph energy source, carbon source and types of organisms
Energy source: Light
Carbon source: organic compounds
Types of organisms: Certain, salt loving, prokaryotes
Chemoheterotroph energy source, carbon source and types of organisms
Energy AND carbon source: Organic compounds
Types of organisms: Prokaryotes, fungi, animals, some plants
Bacteria cell walls
- most bacteria have cell walls, some dont
- composed of peptidoglycan
- Structure of wall determines response to gram satin test
Gram negative bacteria
- have an outer and inner membrane
- cells with no wall also stain negative
- harder to treat with antibiotics bc of outer and inner membrane
- Must be killed more slowly because of LPS
Gram stain test
- Response to gram stain test is determined by structure of cell wall
- Pulls water out of cells using ethanol
- Not related to phylogenetic relationships
Plasmids
extrachromosomal DNA, carry a few genes that are helpful in certain situations such as resistance. can be transferred between cells
Capsule
- found surrounding some bacteria
- slimy
- attracted to water
- stick to surrounding surfaces
Pilus/Pilii
- Many different types
- Cell w/plasmid senses cell w/o plasmid and transfers the plasmid
- can happen between diff. species
Flagellum
- Arose from convergent evolution
- anchored in gram negative membrane
- bigger in eukaryotes than prokaryotes, they also have diff. internal components
- tail made of proteins, spun by internal motor
- delicate
What makes archea unique with their cell membranes?
They have monolayers and ether linkages, thought to help them tolerate harsher conditions
