Term
| 5 basic groups of microbes |
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Definition
- bacteria
- fungi
- viruses
- protozoa
- algae |
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Term
| Bacteria (definition and characteristics) |
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Definition
Unicellular, microscopic, prokaryotic organisms that reproduce by binary fission
Characteristics:
- small
- prokaryotic
- single celled
- complex |
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Term
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Definition
- yeasts: typically unicellular, microscopic, eukaryotic fungi that reproduce asexually by budding
- molds: typically filamentous, eukaryotic fungi that reproduce by producing asexual reproductive spores |
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Term
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Definition
| submicroscopic, acellular infectious particles that can only replicate inside a living host cell |
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Term
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Definition
| typically unicelluar, microscopic, eukaryotic organisms that lack a cell wall |
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Term
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Definition
| eukaryotic microorganisms that carry out photosynthesis |
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Term
| Different shapes of bacteria |
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Definition
- Cocci (chains - ex. streptococcus, clusters - ex. staphylococcus)
- Rods (aka bacilli)
- Vibrio (comma shaped)
- Spirals
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Term
| Prokaryotic cell membrane |
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Definition
- internal to the cell wall
- fluid phospholipid bilayer, lack sterols (except mycoplasmas, which are bacteria that lack a cell wall)
- selectively permeable, moves things by both passive diffusion and active transport
- Other functions:
* Energy production (electron transport)
* Contains bases of bacterial flagella used in motility
* Waste removal
* Formation of endospores |
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Term
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Definition
- contains peptidoglycan, aka murein, (except chlamydia) which consists of a polymer of sugars and amino acids.
- consists of interlocking chains of identical monomers (consists of joined lattice sugars of NAM and NAG)
- peptidoglycan prevents osmotic lysis
- mycoplasmas, bacteria that lack a cell wall
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Term
| Outer membrane in gram negative |
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Definition
- very complex
- porin gatekeeper proteins
- lipopolysaccharides (can cause own rxn) |
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Term
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Definition
puts breaks in the peptidoglycan in order to allow for insertion of peptidoglycan building blocks (monomers of NAG and NAM)
- monomers are attached to the growing end of the cell wall with transglycosidase enzymes, makes it stronger
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Term
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Definition
- found only in gram +
- provides rigidity in cell wall
- polymer of glycerol
- covalently linked to muramic acid and links to various layers of peptidoglycan |
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Term
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Definition
- space between inner and outer membrane.
- may occupy as much as 30% cell volume
- more significant in gram -
- contains enzymes for nutrient breakdown as well as binding proteins to facilitate the transfer of nutrients |
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Term
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Definition
- LPS, aka endotoxin
- consist of:
* lipid A = endotoxin, retains biologic activity when heated
* O-specific antigen - repeating structure on the outermost surface of bacteria, major antigenic determinant
* core polysaccharide |
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Term
| Bacterial secretion systems |
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Definition
- Type 1: (ABC transporters) secretes toxins, proteases, lipases - 3 components
- Type 2: 2 component complex, substrates include extracellular enzymes & toxins from GNs
- Type 3: found in gram -, like molecular syringe |
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Term
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Definition
(1) Crystal violet stain (penetrates cell wall membrane into cell)
(2) Iodine helps stain stick
(3) Organic solvent (decolorizer step) -> see if violet comes out
(4) Pink stain (safrinin) -> only see if violet isn't there |
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Term
| Bacteria that don't stain well with Gram stain |
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Definition
- Acid fast bacteria (walls contain large amounts of waxes interspersed with mureins and lipids - prevents gram stain from sticking)
- Mycoplasmas - permanently cell wall-less bacteria (lost cell wall)
- L forms - bacteria that have lost their cell walls, but can re-grow them
- Spirochetes - visualize with silver stain or by fluorescent microscopy |
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Term
| Structures located outside the cell wall |
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Definition
(1) Glycocalyx
(2) Flagella
(3) Pili |
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Term
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Definition
- capsules and slime layers
- outer viscous covering of fibers that is secreted by virtually all bacteria
- Functions: protection (resist phagocytic engulfment), and allow it to adhere to environmental surfaces |
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Term
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Definition
- ex. dental plaque
- very hard to wash off
- work together as community, quorum sensing
- better able to resist attack by antibiotics and the host immune system |
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Term
| 3 basic parts of bacterial flagellum |
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Definition
- Filament
- Hook
- Basal Body |
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Term
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Definition
- aka fimbriae
- more commonly found on gram -
- most common 2 basic types are used for (1) attachment, (2) conjugation
- Also used for DNA uptake, phage receptors, early steps of biofilm formation, twitching motility, resist phagocytosis, antigenic variation |
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