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54 terms

Microbiology Ch.3 90

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Glycocalyces
Capsule that surrounds a bacteria
Flagella
strands that provide movement for the cell
Name four types of Flagella arrangement:
Monotrichous
Lophotrichous
Amphitrichous
Peritrichous
Monotrichous
one flagella attach to the polar end of the bacterial cell
Lophotrichous
a tuft of flagella attach to the polar end of the bacterial cell
Amphitrichous
flagella at both ends of the cell
Peritrichous
flagella that covers the surface of the bacterial cell
Fimbria
short projections that help bacteria attach to the surface of a host cell
Pili
Attaches to Bacteria cells to pass plasmids along to each other.
Name the (4) External Features a Prokaryotic Cell Possess?
1.Glycocalyces
2.Flagella
3.Fimbria
4.Pili
(3)Structural components for all living cells?
1.plasma membrane
2.cytoplasm
3. nuclear material
(3) Structural components for prokaryotic cells?
1.plasma membrane
2.cytoplasm
3. nuclear material
all external features are optional
(3) Structural components for eukaryotic cells
1.nucleus
2.larger cell size
3.membranebound organellas
Name the cell walls?
1.Eukaryotes
2.Fungi
3.Plants
4.Algae
5.Helminths
6.Protozoans
7.Bacteria-
1.simple carbohydrates
2.chitin
3.cellulose
4.cellulose
5.none
6.none
7.peptidoglycan
Bacteria cell wall?
Peptidoglycan
What are the components of a peptidoglycan?
1.What is the log part composed of (2)?
2. What are the crossbridges composed of?
3. What are the side chains composed of?
1.Log- composed of two alternating sugars
1.NAG sugar
2.NAM sugar
2.What are the crossbridges composed of?
Amino Acids
3.What are the side chains composed of?
Amino Acids
What are the (2) componets of a gram (+) cell wall?
1. Peptidoglycan Layer- Thick
2. Teichoic Acid
What are the (3) components of a gram (-) cell wall?
1.Peptidoglycan Layer-Thin
2.Lipopolysaccharide-outter membrane
3.Porins
Teichoic acid-
What is teichoic acid used for?
contributes to the strength of a gram postive cell wall.
antigen typing
Lipopolysaccharide-
What are the (2) components of a LPS?
outter membrane on a gram (-) cell wall
1. O polysaccharide- O antigen used for serotyping
2. Lipid A
What is the chemical composition of a Endotoxin?
Lipid (Lipid A)
What is the chemical composition of a Exotoxin?
Protein
Overwhelming gram (-) infection from an Endotoxin causes (3)?
1.Fever
2.Shock
3.DIC
Every gram (-) infection causes same response bc?
Endotoxin- Lipid A is always present
Porins-
Function-
Porins- proteins that act as channels.
Function-allow some substances to pass through cell wall.
Why do gram (-) cell walls resist chemicals and antibiotics better than gram (+) cell walls? (2)features
1. LPS-outer lipid membrane
2.Porins- protein channels
These preven chemicals and anitbiotics from penetrating.
(4) steps of a gram stain?
1.crystal violet-primary dye enters both cells. Stain cells purple
2. Iodine applied- mordant and forms larger moleules with crystal violet
3.Acetone OH applied
* Thick peptidoglycan will hold the purple dye and will not wash out. gram + =purple
*Thinner peptidoglycan layer will wash out and release the dye. gram-= colorless
4.Safranin dye= red
Gram- cell will uptake the red dye bc it contains none.
Gram + cell will not uptake the red dye becuase it saturated with purple dye.
The color of a negative gram stain and cell wall type?
The color of a positive gram stain and cell wall type?
Negative gram stain= red thin peptidoglycan, LPS, and porins
Postive gram stain = purple, thick peptidoglycan
What does a negative gram stain mean?
It means the subject of intrest does not stain.
What are the (4) characteristics of a Bacteria that lacks a cell wall?
1.Plemorphic-shape
2.Bacteria does not stain- red gram stain
3.Antibiotics will not work
4.Less protection from environmental extremes.
An example of a bacteria that lacks a cell wall?
Mycoplasma Pnuemoniae causes walking pnuemonia.
What are the effects of each envoriments on a cell?
Isotonic soln
Hypertonic soln
Hypotonic soln
Isotonic soln- no effect on cell
Hypertonic soln=Shrink Cell
Hypotonic soln=Burst Cell
Hypertonic Soln effect on Cell Membrane
1. Plasma Membrane Shrinks
Hypertonic soln effect on a cell with no cell wall?
The Cell will be destroyed.
Hypertonic soln effect on a cell with a cell wall?
The cell will stop growing.
Bacteriostatic-
the bacteria stops growing?
What is used for stoping bacterial growth? (2)
1.high salt
2.high sugar
These hypertonic solutions perserve food by preventing bacteria from growing by shrinking the cell membrane.
Hypotonic soln effect on a cell with no cell wall?
The cell w/no wall will burst and be destroyed.
A cell w/wall will maintain itself.
Name this piece of internal equipment and function?
Spore-oval swelling at the end of rods
Function- preserve the cell when external conditions threaten cell survival.
(3) Conditions when a bacteria turns into a spore?
1.Dry
2.No Food
3.other threat to cell's survival
Sporulates-
When external conditions improve.
1 Spore= 1 Bacteria Why?
No reproduction takes place when a bacteria is in a sporulation.
Do Bacterial Spores Gram Stain?
No Bacterial Spores do not uptake the stain.
What does no cell wall mean about the bacteria?(4)
1.pleomorphic
2.Bacteria cant be gram stained
3.Antibiotics that attack cell walls do not work
4.Bacteria less protection from environmental conditions.
Name two membrane organelles that prokaryotes do not have in their cytoplasm?
1.Golgi Bodies
2.Endoplasmic Reticulum
What are Bacterial Ribosomes called?
What is their function?
Bacterial Ribosomes are 70s
Eukaryotic Ribosomes are 80s
Why do antibiotics attack bacterial ribosomes and not human ribosomes?
Antibiotics only target 70s Ribosomes bc their different from humans
What is the evidence suggesting that mitochondria and chloroplasts could have once free living?
1. both have 70s ribosomes
2.both have double membrane organellas due to endocytosis
What is endosymbiotic theory?
Mitochondria and chloroplasts are actually bacteria in origin.
What are the nonmembraneous organellas?
1.ribosomes
2.Cytoskeleton
3.centrosome
What are membraneous organellas.
1.Nucleus
2.ER
3.Golgi Bodies
4.Lysosomes
5.Peroxisomes
6.Vacuoles
7.Vesicles
8.Mitochondria
9.Chloroplasts
What is contained in the cytoplasm of Prokaryotes?
1.cytsol
2.Nucleoid- a region that contains circular DNA
3.inclusions-reserve deposits. Lipids, Starch, other compounds
Why are endospores important?
endospores are a defensive strategy against threatening external conditions.
What are the nonmembranous organellas in prokaryotes?
1.cytsol
2.cytoskeleton
3.ribosomes