INTRO: 4 TOPICS PRELIMS Flashcards
beneficial aspects of bacteriology
Normal microbiota
Decomposers
Industrial
Producers of Oxygen
Food Chain
found inside our body
Normal microbiota
Producers of Oxygen
algae & cyanobacteria
Microorganisms such as bacteria that are capable of
causing diseases
Pathogenic organisms
Harmless microorganisms that can become pathogenic once the host’s resistance is impaired
Opportunistic pathogens
- Observed a thin slice of cork through a crude microscope
- Introduced the word cell and “Cell theory”
Robert Hooke
Developed the Binomial nomenclature
Carlus Linnaeus
- First to observe live microorganism
o Described the three basic shapes and descriptions of Bacteria, Fungi, and Protozoa
Anton van Leeuwenhoek
The alternative hypothesis that the living organisms
arise from preexisting life
Biogenesis
naming of microorganism according to established rules and guidelines
Nomenclature
Living things comes from non living organisms
Abiogenesis
Created a recipe for mice that he believed that would
create life from non living matter
Jan Baptiste van Helmont
- 1st real experiment to dispute abiogenesis
- Showed that flies and maggots did not arise from decaying meat as others believe, if the meat is
covered to prevent the entry of flies
Francesco Redi
Showed that fluids heated in sealed flask did not
contain microtubes
Lazzaro Spallanzani
Ultra-high pasteurization
100 degree Celsius
chemical breakdown of a substance by bacteria, yeasts, or other microorganism
Fermentation
process of heatingand object like milk being heated and harmful organisms are killed without ruining the quality of the product
Pasteurization
One of the key steps that established the relationship
between microorganisms and disease occurred when a group of French merchants asked Pasteur to find out why wine and beer soured.
Louis Pasteur
Classic Pasteurization
60-62 degree Celsius for 5min or 5 seconds
- Accepted the germ theory of disease and stressed a
need for prevention rather than cure, and continued
to advocate good hygiene and sanitation practices - Advocated for the use of antiseptic before performing
surgeries
Florence Nightingale
Provided experimental steps (Koch’s Postulates) used to prove that a specific microbe causes a specific disease
Robert Koch
inoculated a person with cowpox virus resulting to protection from smallpox.
Edward Jenner
Developed salvarsan (arsenic derivative effective
against syphilis)
Paul Ehrlich
Discovered penicillin, the first antibiotic
Alexander Fleming
Proposed the use of immunology to identify bacteria
according to serotypes
Rebecca Lancefield
Introduced Recombinant DNA which are made from
two (2) different sources
Paul Berg
Bacteria degrade organic matter in sewage & detoxify pollutants
Biomedication
Microbes that are pathogenic to insects but not to humans or animals
Biological Insecticide
Commercial use of microorganisms to produce some
common foods and chemicals
Modern Biotechnology
In replacing a defective gene in human cells, this one uses a harmless virus to carry the missing gene or new gene into host cells and then the gene is picked up into
the chromosomes.
Gene therapy
May use bacteria or fungi to produce a variety of proteins such as vaccines and enzymes.
Genetic engineering
bacteria that are variable in shape
Pleomorphic
shapes of bacteria
spherical
rod-shaped
spiral
2 types of spiral shapes
spirilla
spirochetes
no nuclear membrane or nucleoli
prokaryotes
true nucleus, consisting of nuclear membrane and nucleoli
eukaryotes
- Aka Periplasmic filaments
- Enclosed between cell wall & cell membrane of
spirochetes
Internal Flagella (Axial Filaments)
For adhesion to other cells and surfaces
Fimbriae
External to the cell wall
Glycocalyx
Appendages for mating
Pili
○Highly organized
○Tightly attached
Capsule
Maintain the shape of the cell, protect the cell, and
serves as a point of anchorage of the flagella
Peptidoglycan
Groups Based on Cell Wall Composition
- Gram-Positive Cells
- Gram-Negative Cells
- Atypical Cell walls
○Loosely organized and attached
Slime Layer
A thick, homogenous sheath of peptidoglycan, 20-80 nm thick
Gram-positive Cell Wall
- Linked to the peptidoglycan layer
- Made up of alcohol and phosphate
Teichoic acid
Spans the peptidoglycan layer and linked to the plasma membrane
Lipoteichoic acid
Endotoxin that may become toxic when released
during infections
lipopolysaccharide
An outer membrane containing lipopolysaccharide
Gram-negative Cell Wall
Self-replicating, small circles of DNA
Plasmids
Without cell walls or very little wall material
Atypical Cell Walls
bacterias that has atypical cel walls
mycobacterium
nocardia
mycoplasma
Serves as the site for electron transport system and
serves as “protein synthesis” site for respiration
Cell Membrane
Single, circular DNA molecule
Chromosome
Intracellular storage bodies
Inclusions & Granules
Specialized, resting, dormant cells
Endospores
bacterias that have endospores
Clostridium & Bacillus
Formation of endospores
Sporulation
Return to vegetative growth
Germination
Basis : frequency of traits-sharing
Numerical Taxonomy
“Basic unit” of taxonomy
* Represents a specific, recognized type of organism
Species
Basis: genetic similarity & evolutionary relatedness
Phylogenetic Classification
Basis: Overall similarities
Phenotypic Classification
A group or “level” of classification
Taxonomy
A population of microbes descended from a single
individual or pure culture
STRAIN
Major Nutritional Needs for Bacterial Growth
Carbon Source
Nitrogen Source
Energy Source
Derive energy by photophosphorylation
Phototrophs
Required for synthesis of nucleic acids like DNA and
RNA
Purines & Pyrimidines
Derive energy by oxidative phosphorylation
Chemotrophs
Required for synthesis of proteins
Amino Acids
Needed as coenzyme and functional groups of certain enzymes
Vitamins
tend to require a variety of growth factors
Fastidious organisms
Signs of growth appears at the surface level of broth
medium
Obligate aerobes
Homogenous turbidity in the medium
Facultative anaerobes
Signs of precipitation or turbidity at the bottom of the
medium
Obligate anaerobes
Growth is seen in the sub-surface level of the broth
Microaerophiles
Homogenous growth inside the medium
Aerotolerant anaerobes
cold loving bacterias
psychrophiles
RT bacterias
mesophilic
bacterias that can endure very cold or freezing temerature
psychroduric
heat loving bacterias
thermophiles
bacterias that loves very dry environment
xerophiles
salt-loving bacterias
halophiles
Most indispensable requirement; only common solute in nature that occurs over a wide range of concentration range
Water
Only common solute that occurs over a wide concentration range within the bacterial environment
Salt
ph of most bacteria
pH 6.5-7.5
ph of molds & yeast
pH 5-6
The Four Phases of Bacterial Growth
Lag Phase
Log Phase
Stationary/Plateau Phase
Death Phase
The time it takes for an organism to double its number
Generation Time
orderly increase in quantity of cellular constituents
Bacterial Growth Curve
Adjustment period
Lag Phase
Cellular reproduction stage
Log Phase
Pop density high
Microbes dividing = microbes dying
Stationary/Plateau Phase
Dead/dying microbes > new cells
Decline continues until there is complete cessation
of reproduction
Death Phase
- Single, long piece of circular, double-stranded DNA
- Contain 2000 to 4000 genes.
Chromosome
- Small DNA circles
- Replicate independently
Plasmids
- Mother cell to offspring
- Binary Fusion
Vertical Gene Transfer
- Conjugation
- Transformation
- Transduction
Horizontal Gene Transfer
A recombinase functioning in recombinational DNA
repair in bacteria
ReCa Protein
Bacterial Mating
Conjugation
process of Gene transfer may occur between two different species
Transformation
Transfer of DNA Fragments from one bacterium to
another by a bacteriophage
Transduction
T-phages
* Replicate through the Lytic cycle
Lytic or Virulent Phage
- Phage lambda
- Undergoes replication through the lysogenic cycle
Temperate Phage
When the lytic phages replicate, the capsid sometimes assembles around a small fragment of the bacterial DNA that’s not viral by nature
Generalized Transduction
Initiated by the temperate phage which undergoes
the Lysogenic cycle as it replicates
Specialized Transduction
Any change in the DNA base sequence
Mutation
- May cause plasmids to integrate into the
chromosome - Responsible for the spread of antibiotic resistance
genes
Mobile Genetic Elements
