Prokaryotes and eukaryotes Flashcards
What do large bacteria do to combat SA: volume diffusion?
Invaginated cell membranes increase SA, large intracellular deposits reduce volume, swim
Mesophilic
15 - 60 degrees, e.g. geothermal hotsprings
Thermophilic
60 - 80 degrees e.g. Yellowstone national park
Hypothermophilic
> 80 degrees - colours due to photosynthetic pigments
DNA thermostability
unstable about 90 degrees - hypothermophiles have a higher G and C content and histone-like proteins. Higher salt concs also help
Halophiles
Tolerance to sale e.g. dead sea - intracellular K+ and glycine
Psychrophiles
Grow at 0 degrees, some metabolically active
Acidophilus and alklophiles
e.g. ferroplasma pH 0 and spirulina pH 10.5
Deinococcus radiodurans
can withstand radiation 3000 higher than would debilitate humans
Morphological classification
Colonies, ultrastructural, staining, cilia, flagella, motility mechanisms, endospores, spores, cellular indusions, colour, cell shape and size
Physiological and metabolic classification
C + N sources, cell was cons, energy sources, luminescence, O relationships, pH, osmotic potential
Ecological classification
Life cycle patterns, symbiotic relationships, disease, habitat preferences
Genetic analysis classification
Transformation, conjugation, plasmids, phage-typing
Molecular classification
Based on 16S RNA genes
Molecular phylogenetics
Nucleotide position = character –> genetic drift and comparisons
Genomics
Complete complement of an organism
Metagenomics
Nucleic acid of entire microbial communities studies simultaneously –> microbial diversity
Bacteria
23 phyla, cell walls peptidoglycan - mesh-like structure. Gram staining sorts into different groups
Cyanobacteria
Oxygenic photosynthesis - incurs CO2
Proteobacteria
V couples, over 2000 species - 5 classes
Firmicules
Low G + C gram +ves -> 3 classes
Actinobacteria
High G+C gram +ves e.g. mycobacteria, mycelia acids in cell walls, streptomycin soil - antobiotics
Spirochetes
Helically shapes, motile, gram -ve, human pathogen
Archea
5 phyla, gram +ve/-ve, spherical rod shaped, spiral, lobed, cuboidal, triangular etc.
Cell structure + metabolic systems like bacteria
DNA replication, transcription and translation like eukaryotes
Viruses
Simple, cellular entities. Produce only within living cells –> obligate intracellular parasites, nucleocapsid (nucleic acid genome) and protein capsid
Protists
Eukaryotes, not plants, animals or fungi or a formal taxa. Not pylogentically related, but paraphyletic (common ancestor, but not all I’m group). Some motile, most unicellular
Endosymbiosis
Of chloroplasts and mitochondria (gene transfer) - prokaryote –> eukaryote = flexible cell surface , larger interloping increase SA
PSeudopods
Network of cytoskeletal microfilaments that squeezes cytoplasm forward
Chromalveolate: dinoflagellates
Marine, primary producers, golden brown, some photosynthetic, endosymbionts, some non-photo parasites, 2 flagella
Plantae: red algae
Marine, multicellular and attach substratum, holdfast red = pigment which varies in amounts, some secrete CaCO3
Excavates
euglenoids - unicellular and flagella (crystalline rods), mitochondria disc-shaped cristae
Rhizaria: fradiolarians
Process thin, stiff pseudopods, reinforced by micro tubules, increasing SA for exchange and help float. All marine, secrete glassy endoskeletons, elaborate designed with radial symmetry
Unikonts: slime moulds
Plasmodial/cellular, all motile, endocytosis, form spores on fruiting bodies, cool and moist habitats, forest unfavourable conditions. Cells aggregate and release spores
