microbio ch4 study guide😭😭😭

Shape of Prokaryotic cells

* Bacillus(rod-shaped) \n Coccus (spherical)
* Spiral \n Spirillum \n Vibrio
* Spirochete



Star-shaped



Rectangular

Arrangements of Prokaryotic cells

* Pairs (diplo-)
* Diplococci
* Clusters (staphylo-)
* Staphylococci
* Chains (stepto-)
* Streptococci
* streptobacilli
* Groups of four
* tetrads
* Cubelike groups of eight \n Sarcinae

gram positive cell wall

* Thick Peptidoglycan
* Teichoic acids
* Lipoteichoic acid links cell wall to plasma membrane
* Wall teichoic acid links to peptidoglycan
* Carry a negative charge ›may regulate movement of cations



Polysaccharides and teichoic acids provide antigenic variation



2 ring basal body of flagella



Produce exotoxins



Disrupted by lysozyme



\- Penicillin sensitive

gram negative cell wall

* Thin peptidoglycan
* Extra Outer membrane
* Forms a periplasm between outer membrane and plasma membrane and protect from phagocytes, complement and antibiotics \n Outer membrane is made of:
* Lipoproteins \n Phospholipids lipopolysaccharides (LPS) \n O polysaccharide antigen
* Core polysaccharide
* Lipid A is an endotoxin embedded in the top layer
* Porins(proteins) form channels through membrane



Periplasmic space



4 ring basal body of flagella



Produce endotoxin and exotoxins



Low susceptibility to penicillin



Tetracycline sensitive

gram stain - positive

* Alcohol dehydrates peptidoglycan
* CV-I crystals do not leave

gram stain - negative

* Alcohol dissolves outer membrane and leave holes in peptidoglycan
* CV-I washes out \n Safranin added to stain cells