Lab 5 Flashcards
Glycocalyx
a mix of polysaccharides and polypeptides.
Loosely bound = slime layer
Tightly bound = capsule
Virulence factor
increases the likelihood of an infectious disease
*makes bacterium a more successful pathogen
Phagocytosis
the ingestion of bacteria or other material
Opsonization
an immune process which uses opsonins to tag foreign pathogens for elimination by phagocytes
Biofilms
a collective of one or more types of microorganisms that can grow on many different surfaces.
*increased virulence and antibiotic resistance
Endospores
structures that form inside of some bacteria
the dormant, tough, and non-reproductive structure produced by certain bacteria
Endospore
Germination cycle -
Sporulation cycle -
The germination cycle - is the change of an endospore from its resting stage to an actively growing vegetative cell. This takes place when the external environment is favorable for growth by the provision of essential nutrients and water.
Sporulation cycle - the formation of spores from vegetative cells during unfavorable environmental conditions
Flagella
bacteria appendages that allow bacteria to move
Composed of protein, flagellin
Flagella arrangements
1 at 1 pole
several at 1 pole
1 at each pole
many around the cell
Monotrichous
Lophotrichous
Amphitrichous
Peritrichous
Mordant
combines dye or stain and fixes it to a material
Turbidity
the measure of relative clarity of a liquid
Absorbance
a measure of the capacity of a substance to absorb light of a specified wavelength
Spectrophotometer
shines light through a sample to measure the absorbance of light
*higher the absorbance of light the higher the growth
Blank
a tube that contains only growth factor
what are 2 examples of genre that form endospores
bacillus and clostridium
in what 3 ways does the spore protect dna
- surrounded by thick peptidoglycan and spore coat
- surrounded by acid-soluble proteins
- protected from US radiation
What can destory a endospore
autoclaves
sterilizing gases and liquids
ionizing radiation
Describe a capsule and how it surrounds the cell
Glycocalyx made of polysaccharides & polypeptides that is well organized tightly bound and surround the bacteria cell.
Explain why capsules are consider virulence factors
Because their presence on the bacteria cells increase the chances for serious disease.
Describe a biofilm and the role of capsules in their formation. Give an example of a biofilm
that could form in an infection.
Biofilm community of bacteria that stack to a surface.
Biofilm make the bacteria resistant to antibiotics and increased virulence.
Plaque on our teeth is biofilm that can damage the teeth or even kill us if we don’t take care of it.
Name an encapsulated bacterial pathogen that is a common cause of pneumonia.
Pneumococcus – Streptococcus pneumoniae.
how do flagella cause motility?
the transmembrane electrochemical gradient of ions,
anticlockwise rotation
what must be done to see flagella in a microscope?
They have to be thickened with a mordant
chemotaxis?
do all bacteria have chemotaxis?
Chemotaxis - direct their movements in response to certain chemicals in their environment
not all bacteria do chemotaxis
