Title: Physeo / 12 - Microbiology / 01 - Fundamentals / Section 1 - Bacterial Structure
Tags: Physeo::Microbiology::Fundamentals::BacterialStructure

Q: Bacteria's cytoplasmic membrane consists of a [...] bilayer.
A: phospholipid

Gram positive bacteria's cytoplasmic membrane contains lipoteichoic acids that stimulates host immune response via TNF-alpha and IL-1 release.

Q: Bacteria's cytoplasmic membrane contains [...]-binding proteins ([...]).
A: penicilin; PBPs

Peptidoglycan provides rigidity and structural support to the bacterial cell. It is found in the cell wall.

Q: In gram-[...] bacteria, crystal violet will bind to the [...] cell wall and give a blue appearance.
A: positive; thick

Q: In gram-[...] bacteria, crystal violet will not bind to the [...] cell wall.
A: negative; thin

Q: The [...] is absent in [...] species which have added [...] to maintain rigidity/stability.
A: cell wall; Mycoplasma; sterols
Extra: Since they require sterols to live, can only be cultured using Eaton's agar, which provides the sterols.

Mycobacteria species contain mycolic acids in their cell wall, requiring the use of acid-fast stain.
Extra: The acid fast stain binds to the outer lipids.
Gram-stain of Mycobacterium Tuberculosis
Notice that the organisms appear bright red after the binding of mycolic acids

Q: [...] provides bacterial [...], which extend from the cytoplasmic membrane to the extracellular space.
A: Flagellum; motility
Q: Another name for Pilus is [...].
A: fimbria
Q: [...] allows bacterial to bind to host cells, causing [...].
A: Pilus/fimbria; infection
Comment 3: Pilus extend from the cell wall to the extracellular space.
Q: [...] allows [...] binding during [...] as a way to exchange genetic information.
A: Pilus/fimbria; bacteria-bacteria; conjugation

Q: The bacterial glycocalyx is a network of [...].
A: polysaccharides
Comment: Note: the capsule of Bacillus anthracis is made of poly-D-glutamate
Q: If the bacterial glycocalyx is [...] and [...] attached to the cell wall, it is the [...].
A: disorganized; loosely; slime layer
Comment 2: The slime layer creates a biofilm on prosthetics (eg. S. epidermidis).
Q: If the bacterial glycocalyx is [...] and firmly attached to the cell wall, it is the capsule.
A: organized
Comment 3: This serves as protection from phagocytosis.
Q: The bacterial slime layer glycocalyx creates a [...] on prosthetics (eg. S. epidermidis).
A: biofilm
Text 5: It is loose and disorganized.
Q: The bacterial capsule glycocalyx serves as protection from [...].
A: phagocytosis
Text 6: It is firm and organized.
Pic On All Cards: Also in Gram negative.

Q: During gram staining:
When the crystal violet washes out from gram [...] bacteria, a gram counter-stain with [...] causes a [...] appearance.
A: negative; safranin; red
Comment: Safranin binds to the outer membrane
Q: The bacterial outer membrane contains [...], allowing the [...] of nutrients.
A: porins; transfer
Lipopolysaccharides contain lipid A, core polyssaccharide, and O antigen.
Comment 3: They are embedded throughout the bacterial outer membrane.
Lipid A stimulates host immune response via TNF and IL-1 release causing fever, shock, and diarrhea.
Comment 4: This is called septic shock
Lipid A is found in lipopolysaccharides (LPS) in the bacterial outer membrane.

The periplasm is the space between the outer membrane and cytoplasmic membrane in gram-negative bacteria.
Q: The periplasm accumulates [...] such as B-lactamases.
A: hydrolytic enzymes
Comment 2: While gram positive bacteria do not have a periplasm due to not having an outer membrane, they still have B-lactamases, which is just excreted into the extracellular environment.

Q: An [...] is a layer formed during a [...] state that allows bacteria to resist [...].
A: endospore; dormant; heat, chemicals, dehydration, and starvation
Comment: Allows the bacteria to survive until the environment is safe enough for the bacteria to become metabolically active again.
Q: Endospores are only present in gram-[...] organisms
A: positive
Comment 2: ie. Clostridium and Bacillus
*Not the same thing as using the word spore C.burnetti, Fungi, etc.

Bacterial endospore structure (inner to outer):
Center contains DNA and dipicolinic acid (DPA)
Cytoplasmic membrane (spore core)
Peptidoglycan wall (spore cortex)
Cytoplasmic membrane
Keratin-like protein wall (spore coat)
Exosporium (present only in B. anthracis and B.cereus)

Q: Bacteria have which type of polymerase?
[...] polymerase
A: RNA and DNA

Q: DNA polymerases are responsible for [...], while RNA polymerase is responsible for [...].
A: replication; transcription
Extra: You don't want DNA to be making a lot of mistakes because it can be passed to the progeny.

Q: [...] helps keep the spore [...].
A: Dipocolinic Acid (DPA); dehydrated