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Chlamydia
- Half the size of rickettsia
- Can not be see with light microscope
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Mycoplasma
- Smallest of bacteria
- No cell wall
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Cyanobacteria
- (“Blue-green algae”)
- share structural andbiochemical properties of bacteria
- Have light trapping
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Fungi
- Once considered plants, but plants do not have chitin
- Do not employ photosynthesis
- use performed organic matter from environment: very resilient, important decomposer's of organic material
- Eukaryotes that are divided into two major branches – they exhibit diamorphic growth (adaptability)
- :yeasts – unicellular
- :molds – long chains of cells
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Unicellular Algae
- Plant-like
- use photosynthesis
- differ structurally from mosses, ferns, and seed plants
- two types
- :diatoms(eukaryotic) – important food source in ocean (whales filter water to eat these
- :dinoflagellates – photosynthetic eukaryotescomposed of amoebae in hard shells
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Viruses
- no observable activity except replication
- only function inside living cells
- observed with electron microscope only
- consist basically of nucleic acid and protein
- nucleic acid packaged inside protein: released when virus penetrates cell
- takes over host cell’s structures and enzymes to replicate (cell often destroyed)
- as more cells involved, tissue disintegration occurs (common to all viral diseases)
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Coccus(singular)
cocci(plural)
sphere shape
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Coccus:
Single plane division examples
2plane division
8plane division
Grape like cluster
- : diplococci and streptococci
- : tetrad
- : sarcina
- : staphylococc
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Bacillus(singular) bacilli(plural)
:types
- :rod shape
- Singlebacillus
- Diplobacilli
- Streptobacilli
- Coccobacillus
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Spiral shape
- Vibrio
- Spirillum-relatively thick
- Spirochete-more waves than spirillum and much thinner
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Star shaped and rectangular prokaryotes
- Happens when organism loses their cell wall (for whatever reason)
- Assumes shape based on the influential pressure of their environment
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Pili
appendages that are short,straight hair-like fibers
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Sex pili
transfer genetic material
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Fimbriae
- (attachment pili)
- adhesion to host tissue
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Glycocalyx
adhearing layer of polysaccharides and small proteins
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Capsule
glycocalyx is thick and tightly bound to the cell
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(Glycocalyx) Slime layer
thin, flowing and less tightly bound
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Glycocalyx
: form and purpose
- Formed by various rods and cocci but NOT spiral bacteria
- Purpose: Buffer between cell and external environment
- Prevents nutrients from flowing away
- As a capsule or slime layer – inhibits phagocytosis
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Biofilms definition
slime layers and capsule key elements in formation of a series of encased microcolonies of bacteria
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Biofilms: purpose
- attach to such surfaces as body tissues and Prosthetic devices
- believed that most bacteria within nature live within biofilms
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Cell wall
- prevents bacterial cells from rupturing when water pressure inside is greater than outside
- Responsible for shape of cell
- Serves as point of advantage for flagella
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Operation of flagella in bacteria
- Rotates clockwise until it finds what it is looking for
- Then goes to counterclockwise to move straight ahead
- Reverts back to clockwise rotation when it is looking for something again
- More flagella isn’t always better; the fastest mover happens to have only one flagellum
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CellMembrane
- (Plasma membrane)
- Nutrients are transported into cell
- Transports waste material out of cell
- Anchors the DNA during replication
- Site for enzymes used in energy metabolism
- Consists of 60% protein and 40% phospholipid
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Cytoplasm Gelatenous mass of:
- Proteins(usually in the form of enzymes)
- Carbohydrates
- Lipids
- Nucleic acids
- Salts and inorganic ions
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Cytoplasm Foundation of a cell
- Center for growth and metabolism
- Various organelles found here
- May have plasmids (small closed loops of DNA that are independent of the cell’s chromosome)
- :Relatively few genes
- :Carry genes for toxicity and drugresistance
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Endospores
- Gram positive rods such as Bacillus and Clostridium
- Purpose is for survival not reproduction
- (Give the bacteria an escape in harsh conditions by forming a protective wall around DNA while cell dies)
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Binary Fission
asexual process of replication
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Generation
Time
- (aka Doubling Time)
- Interval of time until the completion of the next cell division
- helps determine how long it will take before disease symptoms appear
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Temperature requirements for Growth:
- Psychrophiles: 0-20 C
- Mesophiles:20-40 C
- Thermophiles40-90 C
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