Microbial physiology

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Basically physiology is how cells and organisms work, Brock said that 'nutrients required; products made'.  Which means that something has to be given in order to for something to be taken.  


In microbioloyg CELL= ORGANISM as mos microbes are only one cell.


There is communication between Prokaryotes:


Auto-induction, also known as quorum sensing, and chemical signals.  In Gram +VE: it is peptide signalling.  This coordinated the synthesis and secretiong in microbes such as Staphylococcus aureus 

In Gram -VE: Acyl homoserine lactone (AHL) signalling.  Threshold of AHL triggers channge in behaviour.  First discovered in Aliivibrio fischeri.

Archaea: AHL signalling to coordinate protease synthesis and secretion.  


There is also locomotion on microbes:

Flagella and Gliding 

and taxix: Chemo or photo (chemicals or light sensitive).


The flagella: Bundles flagella move counter-clockwise and are all together

Tumble is when the flagella are pushed apart  and this gives clockwise movement.  This movement is known as PERITRICHOUS  


Reversible flagella is when the flagella has the trait of moving both clockwise and counterclockwise by altering roation.  

Undirectional flagella is when the cell has to posititon itself in the direction in which it wants to go before flagella rotation.  This is also known as polar as the rotation of the flagella is clockwise only!  Polar is one flagella too!


Movement of flagella is stared when Repellants occupy the transducer (MCP) in the cell wall.  This created CheAP ---> CheA.  The P teh combines wiht CheY with the help of CheZ to becomne CheyP, and it is this molecule that activated the flagllar motor.  


Within the motor there are 4 rings: L ring, P ring, MS ring and C ring.  It is the MS & C ring that turn the motor.  They are intrinsic are located nearer the inside of the cell.  H+ ions travel through Mot protein, both MS and C rings are charged with -ve and +ve charges.  Change in H+ causes the rings to rotate.  


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