Saturday, 14 January 2012

coffee and music reaching its objective

(plural: prosthecae)
a semirigid appendage extending from a procaryotic cell,
with a diameter which is always smaller than that of the mature cell,
and which is bounded by cell wall

eg. Caulobactor sp.

-produce under process sporulation, in response to extreme environmental
-dormant, temporarily non-productive structure
-produce from certain bacteria (firmicutes phylum)
-in the dormant, inert endospore state, bacteria do not metabolize or reproduce, but exist in suspended animation
-it formation tigger by lack of nutrient (usually in G+ bacteria)

6 varieties of locations and shapes for endospore
-central endospore: Bacillus cereus
-terminal endospore: Clostridium tetani;
.can cause tetanus
.endospore can be so large, cell is distended (swell) around endospore
-lateral endospre: Bacillus subtilis

Staining Bacterial Endospore
Normal water-based technique, such as gram stain will not stain these tough, resistant structure.
In order to stain endospores, malachite green must be forced into spore with heat,
in much same way that carbol fuchsin is forced through the waxy mycolic acid layer of Mycobacterium in the Acid-fast stain.

Protocol Staining Endospore

Archae: Morpology

-Methanococcus janaschii
-has numerous flagella attach

2.Coccus: Sarcina
-Methanosarcina barkeri
-a lobed coccus form lacking flagella

-Methanothermus fervidus

4.Elongate Bacillus
-Methanobacterium thermoautotrophicum

A Typical Bacterial Cell
(what we can see)
1.slime layer
5.inclusion body

Fine Structures of Bacteria
1.Surfaces Appandages: -flagella -fimbrae -pili - spines
2.Glycocalyx: -capsule
4. Resting Structures: -endospores
5. Cell Membranes, eloboration of cell membranes and structures in the cytoplasm
6. Cell Wall

Flagella Arrangement
-Monotrichous (one 'tail') -Lophotrichous (many 'tails', one direction)
-Amphitrichous (2 'tails', each at opposite pole of cell)
-Peritrichous (many many 'tails', all direction, all naturally occuring bacteria, motile)

-length: 12nm (Proteus vulgaris), 30nm (Vibrio metschnikovii) -range (15mic.m-20) some 70.
-flagella stain: basic fuchsin and tahnic acid

-fine, proteinaceous, hairlike bristles from the cell surface
-function, in adhesion to other cells and surfaces

Fimbriae Attachment
-survival: aquatic bacteria
-virulent factor: N. gonorrhea enterotoxic strain of E. coli
-M proteins and fimbriae of S pyrogenes: involved in adherence and resistance to phagocytosis
-surface pellicle formation in unshaked culture

-rigid tubular structure made of pilin protein
-found only in G- cells
-functions to join bacterial cells for partial DNA transfer called conjugation

Summary of Characteristic of Typical Bacterial Cell Structure

1.swimming movement
3.virulent factor. eg. H. pylori

Sex Pilus
1.stabilizes mating bacteria during DNA transfer by conjugation

1.attachment to surface: protection against phagotrophic engulfment

Capsule (include "slime layer" and glycolyx)
1.attachment to surfaces against phagocytic engulfment
3.ocassionally killing or digestion
4.reserve of nutrients or protection against desiccation -usually polysaccharide, ocassionally polypetide

-coating of molecule external to the cell wall
-made of sugars and/or proteins
2 type: 1. slime layer - loosely organized and attached
2. capsule layer - highly organized and tightly attached

Function glycolyx:
1.protect cells from dehydration and nutrient loss
2.inhibit killing by white blood cells by phagocytosis, contributing to pathogenicity
3.attachement - formation of biofilms
1. L. mesenteroides - destran (use as stabilizer in syrup)
2. Xanthomonas camperstris - xanthan (use as engine oil)

Capsule -Function:
1.prevent attachment of bacteriophage against antibacterial agent
3.attachment: virulent factors, produce tosins/enzyme and disturbing function of organs against phagocytic engulfmentm ocassionally killing or digestion. 1. B. anthracis 2. C. perfringens 3.S. pneumoniae against desiccation and stabilize culture
-homopolysaccharides and heteropolysaccharides

peptidoglycan >50% dry weight
has teichoic acid and/or teichuronic acid
lipid 1-4% dry weight
No protein

peptidoglycan 10% dry weight
No techoic acid and-
lipid 11-22% dry weight
Has Protein, Lipoprotein, Lipopolysaccharides

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