cell walls-bacteria

[A]

QUESTION???? do cell walls in bacteria prevent cells from dying in hypertonic conditions?????????????

[kiekyon]

yes,

[rg]

cell wall is permeable...but cell membrane is semi-permeable........being permeable it allows any thing to enter without any restrictions.......but cell walls of bacteria(only eubacteria) contain special protiens called PORINS which alter thier sizes accordingly if it has to allow substances to enter cell or not.....so the bacteria will die out of plasmolysis......this forms the basis of salting the food substances for storage purposes.....

[illusions2100]

hi rg i cudnt make out ur point..the cell walls actually cannot prevent da cell from dyin in case they are placed in a hypertonic solution can they?
well u c if a bacterial cell is placed in a hypertonic solution they only thing dat will happen is it will loose its water nd dry out...porins will be able to prevent stuffs from enterin da cell..but will they cell remain alive for a long time if it drys out?

[mkwaje]

Well I believe the CW coupled with the CM can maintain the integrity of the cell in hypertonic solution up to a certain degree. I think that's why different bacteria have different tolerances in salt conditions. Staphylococcus for example, can tolerate higher amounts of salt than some bacteria, that's why salt is incorporated in Staph selective media.

Considering the Archaea, halophiles can survive extremely salty conditions; they have evolved different mechanisms to survive in hypertonic solutions like pumping out salts out of their system.

[pooja vichare]

bacterial cel walls do help to prevent cells from dying in hypertonic conditions,otherwise bacterias wouldn't be found in salt water lakes!!

QUESTION???? do cell walls in bacteria prevent cells from dying in hypertonic conditions?????????????

[mkwaje]

Add'l info: very few true bacteria are found in salt water lakes. Only the extreme halophiles are the ones that can survive in high salt concentrations. But their CW structure is very very different from the typical NAM-NAG chains found in typical bacteria.

[Sang]

Are there anything concern with Gram? I mean Gram + and Gram -?
I have studied it but I don't remember correctly! Please remind me!

[victor]

Yup, gram+ and gram- have a different cell wall.

[Sang]

Now, thanks. i have been reminded!
Gram - has a cell wall with he lipopolisacharid?
Right? That's why they are so dangerous!