Bacterial Cell Structure

Front 1

Basic Cell Structures (Not Special)

Back 1

-cell wall
-plasma membrane
-chromosome (nucleoid)
-ribosomes
-inclusion (granule)

Front 2

Flagellum:
-Attached where?
-3 parts?
-Rotation direction during running? Tumbling?

Back 2

-attached to the cell membrane
-parts: filament, hook, basal body
-running: counterclockwise
-tumbling: clockwise

Front 3

Flagellum:
-Terms that describe how many and location of flagellum on a bacterium?

Back 3

-monotrichous - single flagellum
-lophotrichous - cluster at one end
-amphitrichous - one at each end
-peritrichous - distributed all over cell surface (slowest traveler)

Front 4

Frimbrae:
-Function?

Back 4

-fxn: attachment to target cell; enable colonization

Front 5

Pilus:
-Function?

Back 5

-fxn: allows DNA to be transferred to another cell via conjugation

Front 6

Glycocalyx:
-2 types?
-Function?
-Visualized by?

Back 6

-2 types: slime; capsule
-fxn: adhere to surfaces; incr ability to cause disease (cap); protects against phagocytes (cap) and drying (slime)
-visualized by indian ink stain
*not required for cell growth

Front 7

Gram Staining:
Chemicals and Steps

Back 7

1. crystal violet = staining
2. iodine = fixing
3. alcohol or acetone = decolorization
4. safranin = counterstaining

Front 8

Gram Positive Cells:
-Stain which color?
-Layers?

Back 8

-stain blue/black or purple
-(out) peptidoglycan (thick), periplasmic space, cell mb (in)
-APS: teichoic acid & lipotecihoic acid (unique to gram+)

Front 9

Gram Positive Cells:
-Acidic polysaccharides associated? Bound to?

Back 9

-teichoic acid bound to peptidoglycan
-lipteichoic acid bound to cell mb
*these are unique to gram+ cells and play role in attachment

Front 10

Gram Negative Cells:
-Stain which color?
-Layers?

Back 10

-stain red or pink
-(out) outer membrane, periplasmic spc, peptidoglycan (thin), periplasmic spc, cell mb (in)

Front 11

Gram Negative Cells:
Outer Membrane:
-Contents?
-Function?

Back 11

-contents: bilipid layer containing LPSs and porins (lets thru small hydrophilic molecules)
-fxn: permeability layer to large molecules (lower permeability than gram+)

Front 12

Gram Negative Cells:
Outer Membrane:
Lipopolysaccharides:
-Composed of?
-Activates what in animals?

Back 12

-composed of: lipid A (toxic to animals), core polysaccharide, O antigen
-activates monocytes and complement sys -> autoimmune response

Front 13

Peptidoglycan:
-Function?
-Subunits composed of?
-Bridge linking subunits?

Back 13

-fxn: rigidity and porosity
-composed of tetrapeptide (prot) bound to NAM (sugar) bound to NAG (sugar)
-subunits linked by peptide bridge formed by tetrapeptide and pentaglycine peptide

Front 14

Beta Lactamase:
-Found where?
-Function?

Back 14

-B-lactamase is an enzyme found in the periplasmic spc.
-fxn: degrade penicillin = resistance

Front 15

Acid Fast Stain (Ziehl-Neelsen Stain):
-Visualizes what?
-Chemicals and steps?

Back 15

-visualizes acid fast bacteria, which have chemically unique cell walls surrounded by mycolic acid
1. carbol fuchsin = staining
2. mixed with phenol = fixing
3. acid/alcohol = decolorization
4. methylene blue = counterstain (acid fast bacteria stain pink)

Front 16

Order of amount of peptidoglycan found in cell wall types

Back 16

1. gram+ (most peptidoglycan)
2. gram-
3. acid fast

Front 17

Defensin is secreted by host cells to attack which part of the bacterial cell?

Back 17

-cell mb

Front 18

Chromosome:
-Structure?
-Condensed by?

Back 18

-structure: ds DNA, circular
-condensed by DNA gyrase (not histones)

Front 19

Ribosome:
-Subunits?

Back 19

-subunits: 50S and 30S (as opposed to humans' 60S and 40S subunits)

Front 20

Inclusions (Granules):
-Function?

Back 20

-fxn: intracellular storage

Front 21

Spore (Endospore):
-Function?
-3 Layers?
-Visualized by?

Back 21

-fxn: very resistant to heat, radiation, etc. -> enables survival in harsh conditions
-layers: [out] exosporium (prot), spore coat (prot), cortex (peptidoglycan) [in]
-visualized by malachite green stain