3. Composition of microbial world 2 Flashcards
Prokaryotes
- bacteria, archea
– similar in size and shape - lack membrane-bound nucleus
- lack membrane-bound organelles
Bacteria
- prokaryotic
- peptidoglycan cell walls
- gram-positive; gram-negative
– structure of cell wall
– gram-negative can be antibiotic resistent
what are peptidoglycan cell walls
- combination of peptide bonds & carbohydrates
– peptide (amino acids)
– glycan (sugars) - attacked by pennisylin
what are the arrangements of bacteria cells
- coccus (spherical)
- bacillus (rod shaped)
- spirillium (sprial)
- vibrio (crescent like)
- spirochete
- filamentous bacteria
- cells will clump together if growth conditions are not good
– formations depends on growth conditions
how to bacteria reproduce
- binary fission
– daughter cells identical to mother
how does binary fission work
- replication of DNA
– duplication of chromosome - cell growth
– continued cell growth of cell - segregation of DNA
- splitting of cells
– division into two cells
what are archaea
- prokaryotic
- diverse physiology
- range of single cell morphologies to filaments and even aggregates (0.1 - 15 micrometers)
- hard to culture for biologists in lab conditions
how do archaea have diverse physiology
- found to live in extreme environments
– hot springs
– geysers
– gamma rays / UV radiation
what do archaea include
- methanogens
- extreme halophiles
- extreme thermophiles
how do archaea differ from bacteria
- cell wall structure
– lacks peptidoglycan - unique membrane lipid structure
how is archaea membrane structure unique
- unique lipid structure
- side chains connected to glycerol backbone by ether bonds
– instead of ester - side chains branched
– phytanyl sidechain
– sometimes form monolayer membrane - ether linkages vs. ester linkages
what are eukaryotes
- multicellular / unicellular
- true membrane-bound nuclei
- DNA orgaises into chromosomes
- cell reproductions by mitosis and meiosis
- specific cellular functions in different organelles
– eg. mitochondria respiration
– eg. chloroplast photosythesis
how are eukaryotic cellular functions specific in different organelles?
- specific cellular functions in different organelles
– eg. mitochondria respiration
– eg. chloroplast photosythesis
what are fungi
- multi/unicellular
- saprophytes
- rigid cell walls (non-motile)
- filamentous (hyphae)
- secrete degradative enzymes into environments —- cellulases
– proteases
– amylases
what are fungi cell walls made up of
- chitin
– complex polysaccharide
what are fungi applications
- pulp and paper industry
- food industry (penicillium roqueforti - in cheese)
what is yeast
- unicellular
- cell wall of chitin
- asexual/sexual reproduction
what are the applications of yeast
- food industry
– beer, cheese, bread - pharmaceutical industry
– recombinant proteins
what are microalgae
- unicellular
- asexual / sexual reproduction
- photosynthetic
– chloroplasts
– sequester CO2
what are the applications of microalgae
- pharmaceutical
– omega 3 fatty acids - biofuel
– biodiesel - food industry
–pigments
what are viruses
- acellular
- DNA / RNA core
- enclosed by coat of proteins
– may be lipids
what is the coat of viruses
- coat of proteins
- may be closed by lipid envelope
how do viruses reproduce
- only within living cells
how are viruses classified
- nucleic acids characteristics
- capsid symmetry
- their host
- diseases they may cause
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- Nuclear envelope
- absent
- absent
- present
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- Membrane-enclosed organelles
- absent
- absent
- present
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- peptidoglycan in cell wall
- present
- absent
- absent
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- membrane lipids
- unbranched hydrocarbons
- some branched hydrocarbons
- unbranched hydrocarbons
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- RNA polymerase
- one kind
- several kinds
- several kinds
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- Initiator amino acid for protein synthesis
- formyl-methionine
- methionine
- methionine
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- introns in genes
- very rare
- present in some genes
- present in many genes
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- Response to antibiotics streptomycin and chloramphenicol
- growth inhibited
- growth not inhibited
- growth not inhibited
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- histones associated with DNA
- absent
- present in some species
- present
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- circular chromosome
- present
- present
- absent
how are the three domains of life compared?
Bacteria, Archaea, Eukarya:
- Growth at temperatures >100 ‘C
- no
- some species
- no
