Microbiology summary
L0 Origin and Evolution of microbial life on earth
Earth: a time line
Too hot/no water -> no nothing
Rocks!
Water, CH4 -> organic molecules
Subsurface hypothesis (keep on reading)
Stromatolite structures in rock = fossilized microbial mats,
filamentous prokaryotes; life! 3.5 billion yrs ago
LUCA
Division Bacteria/Archaea
Anoxygenic photosynthesis -> uses sulphur
Oxygenic photosynthesis
Theories:
- Panspermia
- Surface hypothesis
- Subsurface hypothesis:
o In sea, near underwater volcanos:
mineral pores form first biological compartments -> compartments allow coupling of
energetic reactions: molecular replication -> lipid bilayers form, take place of
compartments = cells
o Prebiotic chemistry -> RNA -> Proteins -> DNA -> LUCA -> lipids/cell walls -> dispersal
Primitive metabolisms:
- Bacteria: acetogenesis = makes CH3COOH
- Archaea: methanogenesis = makes CH3
Endosymbiosis -> eukaryotes
rRNA from small ribosomal subunit universally used for phylogenetic tree:
- Prokaryotes: 16S rRNA
- Eukaryotes 18S rRNA
L1 Microbiological organisms
Microorganism = small organism consisting of one cell or a cluster of cells
- Can be prokaryotic or eukaryotic
- In nature: live in microbial community, mixed species
Structure:
- Cell wall(s) = gives structural strength
- Cytoplasmic membrane = outer layer of cell
- Cytoplasm
- Ribosomes = synthesize proteins
- Chromosome = contains genetic information
Eukaryotes: have organelles with specific function + membrane bound, usually larger
, All cells: Most cells:
Metabolism Differentiation (spores)
Growth Communication
Evolution (quickly) Genetic exchange (plasmids)
Motility (flagella)
Metabolism = all chemical reactions in the cell
- Catabolism = makes energy (ATP)
o Phototrophs = use light as energy source
Aerobic photosynthesis
Anaerobic photosynthesis
o Chemotrophs = uses molecules as energy source
Chemoorganotroph = uses organic molecules
Chemolithotroph = uses anorganic molecules
- Anabolism = makes biomass (macromolecules)
o CO2 as C-source = autotrophs, most chemotrophs, all phototrophs
o Organic compounds as C-source = heterotrophs
Microscopy:
- Light microscopy:
o Bright field microscopy = light form under sample, usual
o Dark field microscopy = light from the side, dark background
o Phase contrast microscopy = enlarges wave length differences
o Fluorescence microscopy = for organisms that are autofluorescence or stained
- Electron microscopy:
o TEM = looks at inside, make very very thin sample, electrons go through sample
o SEM = looks at surface, coated in gold, reflects electrons
L2 Transport/Morphology/Structures
Major questions of 19th century:
- Does spontaneous generation occur?
- What is the nature of infectious diseases?
Pasteur: spontaneous generation does not occur
Koch: found link between microbes and diseases
Beijerinck: environmental biology, enrichment culture technique
Winogradsky: specific bacteria + their biochemical transformations, chemotrophy/autotrophy
Griffith + Avery-MacLeod-McCarty: plasmids
Woese: phylogenetic tree, archaea
Macronutrients = needed in large amounts,
Micronutrients = needed in small amounts
, Needed in all cells (macronutrients):
- C = major element
- N = proteins, nucleic acids, metabolism
- 0 + H = water
- P = phospholipids
- S = amino acids
- K = enzyme activity
- Mg = ribosomes
- Ca/NaCl = marine microbes, keep osmobalance
Micronutrients:
- Fe = cellular respiration
- Trace metals = enzyme cofactors
- Growth factors = vitamins, cofactors, specific amino acids
Nutrients into cell -> active transport -> needs ATP
ATP synthesis = electron transport chain + proton motor force (pmf)
1. Enzymes in membrane do metabolism: e to next enzyme, H out of cell
2. H diffuses back into cell at ATPase + e
3. H used to make ATP from ADP + P
Active transport:
- Simple transport
o Uses pmf
o Symport = 2 particles together in
Antiport = 1 in 1 out together
- Group translocation
o Uses glucose + P
o Substance chemically modified before entering
- ABC-system = ATP binding casset
o Uses ATP
o Periplasmatic protein takes substance through transportprotein
Morphology:
- Coccus
- Rod
- Spirilla
- Appendaged
- Spirochete
- Filamentous
L0 Origin and Evolution of microbial life on earth
Earth: a time line
Too hot/no water -> no nothing
Rocks!
Water, CH4 -> organic molecules
Subsurface hypothesis (keep on reading)
Stromatolite structures in rock = fossilized microbial mats,
filamentous prokaryotes; life! 3.5 billion yrs ago
LUCA
Division Bacteria/Archaea
Anoxygenic photosynthesis -> uses sulphur
Oxygenic photosynthesis
Theories:
- Panspermia
- Surface hypothesis
- Subsurface hypothesis:
o In sea, near underwater volcanos:
mineral pores form first biological compartments -> compartments allow coupling of
energetic reactions: molecular replication -> lipid bilayers form, take place of
compartments = cells
o Prebiotic chemistry -> RNA -> Proteins -> DNA -> LUCA -> lipids/cell walls -> dispersal
Primitive metabolisms:
- Bacteria: acetogenesis = makes CH3COOH
- Archaea: methanogenesis = makes CH3
Endosymbiosis -> eukaryotes
rRNA from small ribosomal subunit universally used for phylogenetic tree:
- Prokaryotes: 16S rRNA
- Eukaryotes 18S rRNA
L1 Microbiological organisms
Microorganism = small organism consisting of one cell or a cluster of cells
- Can be prokaryotic or eukaryotic
- In nature: live in microbial community, mixed species
Structure:
- Cell wall(s) = gives structural strength
- Cytoplasmic membrane = outer layer of cell
- Cytoplasm
- Ribosomes = synthesize proteins
- Chromosome = contains genetic information
Eukaryotes: have organelles with specific function + membrane bound, usually larger
, All cells: Most cells:
Metabolism Differentiation (spores)
Growth Communication
Evolution (quickly) Genetic exchange (plasmids)
Motility (flagella)
Metabolism = all chemical reactions in the cell
- Catabolism = makes energy (ATP)
o Phototrophs = use light as energy source
Aerobic photosynthesis
Anaerobic photosynthesis
o Chemotrophs = uses molecules as energy source
Chemoorganotroph = uses organic molecules
Chemolithotroph = uses anorganic molecules
- Anabolism = makes biomass (macromolecules)
o CO2 as C-source = autotrophs, most chemotrophs, all phototrophs
o Organic compounds as C-source = heterotrophs
Microscopy:
- Light microscopy:
o Bright field microscopy = light form under sample, usual
o Dark field microscopy = light from the side, dark background
o Phase contrast microscopy = enlarges wave length differences
o Fluorescence microscopy = for organisms that are autofluorescence or stained
- Electron microscopy:
o TEM = looks at inside, make very very thin sample, electrons go through sample
o SEM = looks at surface, coated in gold, reflects electrons
L2 Transport/Morphology/Structures
Major questions of 19th century:
- Does spontaneous generation occur?
- What is the nature of infectious diseases?
Pasteur: spontaneous generation does not occur
Koch: found link between microbes and diseases
Beijerinck: environmental biology, enrichment culture technique
Winogradsky: specific bacteria + their biochemical transformations, chemotrophy/autotrophy
Griffith + Avery-MacLeod-McCarty: plasmids
Woese: phylogenetic tree, archaea
Macronutrients = needed in large amounts,
Micronutrients = needed in small amounts
, Needed in all cells (macronutrients):
- C = major element
- N = proteins, nucleic acids, metabolism
- 0 + H = water
- P = phospholipids
- S = amino acids
- K = enzyme activity
- Mg = ribosomes
- Ca/NaCl = marine microbes, keep osmobalance
Micronutrients:
- Fe = cellular respiration
- Trace metals = enzyme cofactors
- Growth factors = vitamins, cofactors, specific amino acids
Nutrients into cell -> active transport -> needs ATP
ATP synthesis = electron transport chain + proton motor force (pmf)
1. Enzymes in membrane do metabolism: e to next enzyme, H out of cell
2. H diffuses back into cell at ATPase + e
3. H used to make ATP from ADP + P
Active transport:
- Simple transport
o Uses pmf
o Symport = 2 particles together in
Antiport = 1 in 1 out together
- Group translocation
o Uses glucose + P
o Substance chemically modified before entering
- ABC-system = ATP binding casset
o Uses ATP
o Periplasmatic protein takes substance through transportprotein
Morphology:
- Coccus
- Rod
- Spirilla
- Appendaged
- Spirochete
- Filamentous
