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Micro
Week 1a - Bacterial Cytology
23
Accounting
Pre-School
03/01/2013

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Term
What is in gram stain?
Definition
-Crystal violet (primary stain)
-Gram's iodine (mordant; sets stain)
-Ethyl alcohol (decolorization)
-Safranin (counterstain)
Term
What is and is not in the cytoplasmic membrane?
Definition
-It is actually more protein (70%) than phospholipid (30%)
-It contains no sterols; except for **mycoplasma species which lack a cell wall
-Mycoplasma pneumonia causes walking pneumonia
Term
What are the two types of glcocalyces?
Definition
-Glycocalyx is a general term for "sugar-coat"
-When it is tight and distinct we call it a **capsule
-When it is irregular and diffuse we call it a **slime layer
Term
What test do we use that relies on the presence of a capsule?
Definition
-The Quellung reaction
-Involves antibodies that bind to, and change the appearance of the capsule; enlarges and becomes clear
Term
What is the name for capsular antigens?
Definition
-K antigens (think KaKaKaKapsular)
-Can be used in some vaccines like for S. pneumoniae and N. meningitidis
Term
What are the different types of pili? What is another name for pili? What is the protein type?
Definition
-Pili; aka fimbriae

-Can be *F pili; sex pili for conjugation (think, fucking-pili)
-Common pili are for cell adherence
-Can be used in virulence; N. gonorrhoeae

-Composed of pilin (pilE)
Term
What are flagella antigens called? What do they use for energy? What are the different arrangements for flagella?
Definition
-H antigens (think Hairy)
-They use the proton motive force directly for energy (and why wouldn't they since the proton pumps are directly in the pm for bac.)

Arrangements;
-Monotrichous; one only
-Lophotrichous; multiple, all together
-Amphitrichous; two, one at each end
-Peritrichous; bunch all over
Term
What is the flagellar attachment structure in gram-?
Definition
-L,P,S,M rings in the outer membrane, pep layer, periplasmic space, and cytoplasmic membrane, respectively

-L for last
-P for pep layer
-S for space
-M for membrane
Term
What are the ribosomal subunits and important subsubunits?
Definition
-70S is the whole
-30S subunit (16S + proteins)
-50S subunit (23S + 5S + proteins)
Term
What do we see in a high concentration in spores? What gram type can make them?
Definition
-Calcium dipicolinic acid
-Only gram+ can make them (not all g+)
Term
What are the layers of a spore?
Definition
-Core, pm, wall (normal), cortex (special pep), keratin coat, exosporium (protein lipid membrane)
Term
What are the two subunits composing peptidoglycan?
Definition
-NAG; N-acetylglucosamine (aka GluNAc)
-NAM; N-acetylmuramic acid (aka MurNAc)
-Both are amino-sugars

-A pentapeptide is attached to MurNAc to complete the peptidoglycan monomer (one a.a. chopped off later)
Term
What is the pentapeptide chain for gram+ and gram-
Definition
-Gram+; L-ala, D-glu, L-lys, D-ala, D-ala
-Gram-; L-ala, D-glu, DAP, D-ala, D-ala

-DAP stands for meso Diaminopimelic acid
Term
Go through the steps for peptidoglycan synthesis?
Definition
1. UDP is loaded up onto *GlcNAc which is then made into **UDP-MurNAc (uses MurA&B)

2. The *five AAs are loaded onto UDP-MurNAc (MurC-F)

3. UMP is released as MurNAc is attached to **bactoprenol in the plasma membrane (call this lipid I)

4. **GlcNAc is attached using MurG (call this lipid II)

5. A **pentaglycine unit is attached to the middle peptide (either L-lys for gram+, or DAP for gram-)

6. Bactoprenol uses the pyrophosphate bond to *translocate the building block outside the cell
===============V===============
7. **A transglycosylase attaches the MurNac (with the peptide) to the nascent pep chain

8. Finally, a **transpeptidase links the *pentaglycine to the first **D-ala of the nacent chain and cleaves the *terminal D-ala for the energy

-Note; *carboxypeptidases are what do the actual cleaving of the terminal D-ala units (probably a big enzyme)
Term
Which are the "penicillin binding proteins"?
Definition
-Those are the transpeptidases
-PBP can be used interchangeably with transpeptidase
Term
What is the attachment point for teichoic acid in pep? How is teichoic acid immunogenic? What is it's role, and what does it compare to?
Definition
-Attached via a phosphate group to muramic acid in peptidoglycan of *gram+ bacteria
-Remember, it is lipoteichoic acid when attached to the membrane (functions to hold the two together)

-It is immunogenic by activating the *alternative pathway of complement (no Ig needed) (similar to LPS in G-)

-It also plays a role in cell adherence (similar to *pili in G-)
Term
What is the O-antigen? How long is it? What is it's purpose?
Definition
-It is the immunogenic portion of LPS in gram- bac
-It is a carbohydrate chain, 50-100 units in length
-It protects bac from bile salts, antibiotics, etc.

-It is protective for the bac, but also immunogenic
-It allows us to serotype (distinguish) some strains
Term
What is the core polysaccharide, and what does it have?
Definition
-It is the shorter (9-12 sugars) less variable polysaccharide core to LPS that contains a unique *KDO group
-(2-keto-3-deoxyoctulosonic acid)
Term
What is lipid A, and what is in it?
Definition
-It is the toxic part of endotoxin (i.e. LPS)
-Contains *phosphorylated D-glucosamine with FA attached
-Most common FA is *beta-hydroxymyristic acid
Term
What is LOS? Where do we find it?
Definition
-It means lipooligosaccharide
-It is like LPS but without the O antigen
-Present in N. gonorrhoeae & N. meningitidis
-It is readily shed and an important virulence factor
Term
What does lysozyme do? What will it produce upon treatment of gram+ & gram- bacteria?
Definition
-Lysozyme hydrolyzes the *GlcNAc-MurNAc bond
-Both this and penicillin produce protoplasts (cell wall gone) in gram+ and spheroplast (partially gone) in gram- bac
Term
What makes acid-fast bacteria acid-fast? What is the stain? What are some examples?
Definition
-Acid-fast bacteria have *mycolic acid in the cell wall that is the basis for the staining method
-They resist the normal dilute acid wash decolorization of normal staining (hence the name acid-fast)
-The stain used has carbolfuchsin (stains red)

-**Mycobacteria and nocardia species are examples
Term
Which is the bacteria with no cell wall. Give an example and what it causes?
Definition
-Mycoplasma species lack the cell wall, and instead have sterols similar to what we possess (cholesterol)
-M. pneumoniae causes walking pneumonia
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