The Naked Scientists

The Naked Scientists Forum

Author Topic: What causes a cell to either have a wall or not have a cell wall?  (Read 12542 times)

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
I am meaning like with "Mycoplasma Pneumoniae"

It has no cell wall, only a cell membrane.
« Last Edit: 27/11/2007 12:27:04 by Karen W. »


 

Offline Carol-A

  • Sr. Member
  • ****
  • Posts: 141
    • View Profile
Hmmm. Well the simple answer is the DNA it has, it either codes for cell wall or not. If there are two varieties if the same bacteria, one with a cell wall and one without, it is a simple mutation that stops the cell wall being made. Usually that would mean the bacteria would die, but for some it makes no difference, and may make them resistant to some antibiotics (penicillin)
 

another_someone

  • Guest
Usually that would mean the bacteria would die, but for some it makes no difference, and may make them resistant to some antibiotics (penicillin)

Sorry, I don't understand - how can a cell not have a wall (I understand that the nature of the wall can be different, but is not the wall what keeps the metabolic processes of the cell within, and the outside world without)?  To me, to talk about a cell without a wall is like talking about an animal without skin - how can this be so?
 

Offline _Stefan_

  • Hero Member
  • *****
  • Posts: 814
    • View Profile
    • My Photobucket Album
I think you've got cell wall and cell plasma membrane confused. Some(most?) bacteria have a cell wall which surrounds the cell membrane. Plant cells also have a cell wall surrounding their cell membrane.
 

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
The reason I said that is because that is one of the problems I have, what my doctor says is thatr this bacteria is different then most and lacks a cell wall which would normally enable it to be treated with penicillia or normal antibiotics, but because of its lack of wall it has to be treated with a second generation Macrolide antibiotic.. See wiki Article! This is one of two they have found... but thus why my question.. why does it not have a cell wall and only a cell membrane??

http://en.wikipedia.org/wiki/Mycoplasma_pneumoniae

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Mycoplasma pneumoniae
Scientific classification
Kingdom:    Bacteria
Division:    Firmicutes
Class:    Mollicutes
Order:    Mycoplasmatales
Family:    Mycoplasmataceae
Genus:    Mycoplasma
Species:    M. pneumoniae
Binomial name
Mycoplasma pneumoniae
Somerson et al., 1963
Mycoplasma pneumoniae as the cause of diseases classified to other chapters
Classification & external resources ICD-10    B96.0
ICD-9    483.0

Mycoplasma pneumoniae is a very small bacterium, in the class Mollicutes. This class of organisms lack a peptidoglycan cell wall present on all other firmicute bacteria. Instead, it has a cell membrane which incorporates sterol compounds, similar to eukaryotic cells. It obtains these sterols from the host serum, allowing it to retain a simple structure. Lacking a cell wall, these organisms are resistant to the effects of penicillins and other beta-lactam antibiotics, which act by disrupting the bacterial cell wall.
« Last Edit: 27/11/2007 13:40:28 by Karen W. »
 

another_someone

  • Guest
I think you've got cell wall and cell plasma membrane confused. Some(most?) bacteria have a cell wall which surrounds the cell membrane. Plant cells also have a cell wall surrounding their cell membrane.

Thanks - I had not realised the distinction.  So a cell wall is merely armour plating, and the cell membrane is merely a leather jerkin, over which some cells lay the armour plate.
 

Offline Carol-A

  • Sr. Member
  • ****
  • Posts: 141
    • View Profile
Yes, the cell membrane is what keeps the inside in and the outside out, and decides what can go in or out. The cell wall is for strength, but lots of organisms don't have a cell wall. The bacterial cell wall is what is attacked by penicillin.
 

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
Which is why they will have to use a different type of antibiotic to treat this for me.. not your normal antibiotics. because they require the cell wall in order to kill the bacteria  right?

So for some reason the other antibiotis are able to fight the bacteria that do not have cell walls, Right?

So what happens in a bacteria that causes it to develope without a cell wall and only have a membrane?
 

manicgeek

  • Guest
So what happens in a bacteria that causes it to develop without a cell wall and only have a membrane?
A genetic mutation... hasn't that been said already ?
 

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
Well.. I am still confuddled about this!
 

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
So what happens in a bacteria that causes it to develop without a cell wall and only have a membrane?
A genetic mutation... hasn't that been said already ?

So if its a genetic mutation... does this mean I was born with it? Or just Pre disposed to an infection which effects the cells.. I was told they don't multiply the same as a cell with a wall that they attach themselves to other tissue or organs or something like that. can someone explain this to me????
 

manicgeek

  • Guest
Born with what ?

What a cell does/is is determined by it's genetic sequence.

Bacteria are complete cell organisms, as opposed to viruses which generally aren't.
The gene sequence in a bacteria cell determines if it has a cell wall or not, and a mutation of the sequence can change that behaviour. So a cell can evolve (it's line of cells) by reproduction to not have a cell wall, hence the children of a 'walled' cell might not have a 'wall', or vice versa.

Viruses are incomplete DNA sequences, which hijack a host cell, and use it's reproductive cycle to produce copies of itself, which in turn attempt to hijack more cells.

Bloody clever stuff eh? I only wish we understood it ;)
 

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
I just meant that our genetics are made up before were born with a certain genetic make up...

So.... with this bacteria I have developed they tell me the two have no cell walls thus being harder for them to kill with reg. antibiotics.. She said the first coarse would run 4 weeks and then they will check its effectiveness on the  bad bacteria....

It is clever but I am curious about treating these unwalled bacteria I have!
 

Offline Carol-A

  • Sr. Member
  • ****
  • Posts: 141
    • View Profile
If the bacteria have cell walls or not is up to the bacterium, not you! Different types of Antibiotics can disrupt bacterial cells in other ways than damaging the cell wall. There are antibiotics that stop bacterial cell division or protein synthesis.
 

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
If the bacteria have cell walls or not is up to the bacterium, not you! Different types of Antibiotics can disrupt bacterial cells in other ways than damaging the cell wall. There are antibiotics that stop bacterial cell division or protein synthesis.

so say with this particular bacteria... How does it spread.. or whatever it does??? Does it divide, as you speak of stopping cell division. Does that mean the bacteria will remain in my body but the meds will only stop it from dividing and multiplying? Does that mean it will become dormant but not really go away? Will it further damage more organs etc?
 

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
I found this little bit. It seems to tell me some more about this ..as far as how it attaches itself..

http://www.mycoplasmasupport.org/Web_pages/Mycoplasma_Overview/how_does_myco_cause_illness.htm

HOW MYCOPLASMA CAUSES ILLNESS
Introduction
What Is Mycoplasma?
History of Mycoplasma
How Mycoplasma
Causes Illness
What Illnesses Result From Mycoplasma
Testing for Mycoplasma
Transmission of Mycoplasma
Mycoplasma Treatment
Overview References
   

A person sick with a mycoplasma infectionSome mycoplasma belong to the normal flora and can exist in the oral cavity and gut without causing problems. Baseman and Tully (1997) explain that a mycoplasma infection may be contracted early in childhood. Then, depending upon genetic predisposition, it may enter certain cells and lay dormant for 10, 20 or 30 years. The mycoplasma is a slow-growing, stealth-type organism. Once inside the body, it can initially activate the immune system, and then successfully hide from it within the host's own immune cells. Consequently, the immune system is overactive but ineffective. Mycoplasma can then circulate throughout the body while inside a white blood cell and go wherever a white blood cell can go. Once it reaches a distant site, it can emerge from the white blood cell and invade another type of cell. It can cause infection deep within any or all organs. It can even cross the blood/brain barrier and cause brain and spinal infection. Mycoplasmas have also been known to cross the placental barrier to an unborn fetus. The authors further explain that if a trauma occurs such as an accident, severe stress or a vaccination, the mycoplasma can become triggered and reactivate.

Data from a recent study indicated that pathogenic mycoplasmas reside and replicate intracellularly over extended periods in human cells ( Dallo, & Baseman, 2000) The reactivated organism then grows slowly using a very low metabolic activity similar to hibernation (Razin & Tully, 1995) . Periodically, the organisms become more active and then again go into a resting phase with low metabolism. This slow growth pattern of the mycoplasma organism contributes to the chronic nature of the illness and the difficulty in diagnosis. Dallo and Baseman (2000) also demonstrated that the mycoplasma may be able to circumvent conventional antibiotic therapy and immune surveillance to establish chronic infections.

Mycoplasmas grow intracellularly by up-taking cholesterol from host cells. In the process, the cell ruptures and its remains, including a piece of the cell membrane attached to the mycoplasma, is dumped into the bloodstream, causing an autoimmune reaction (Baseman & Tully, 1997). When the immune system attacks the mycoplasma, it also gets “turned on” to attacking the host cell membrane. Autoimmune conditions associated with mycoplasmas include arthritis, Fibromyalgia, myositis, thyroid dysfunction (Hashimoto’s or Grave’s Diseases), adrenal dysfunction, signs and symptoms of Lupus, Multiple Sclerosis, and Lou Gehrig’s Disease (Nicolson, 1998)

(Created 6/10/05 by Sharon Briggs)
 

Offline MayoFlyFarmer

  • Hero Member
  • *****
  • Posts: 863
    • View Profile
    • http://www.myspace.com/wiguyinmn
karen, i think i see where people aren't really undrestanding your question and you aren't really undrestanding their answers.  your question of why don't mycoplasma have cell walls is kind of like asking why don't humans have wings.  the logic that because some bacteria have cell walls-they all should have cell walls, is like the logic birds have wings, why don't all vertebrates have wings?  the truth is that we have evolved differently than birds and have developed different survival strategys than them that don't require wings.  just like mycoplasma have evolved differently than other bacteria and likely have a different survival strategy that doesn't require a cell wall, and likely would be hindered by one.  the question of exactly how they survive that they're better off without one, i don't know enough about them to tell you that.

as far as the antibiotics go, it sounds like you've figured this out; but i have a good analogy.  if you wanted to know how to kill a person and i told you to stab them in the heart; that would be an effective strategy; and you could go around killing anyone you wanted by stabbing them in the heart.  however, imagine if a strain of people evolved that didn't have hearts.  (i know this would never happen, but just imagine) it wouldn't be a very useful strategy to stab them in the heart.  you couldn't kill them that way.  you would need to attack a part of them that they actually have.  all of the early antibiotics we have were designed to attack a bacteria's cell wall, this was effective not only because most bacteria have cell walls and thus they were killed, but also because we humans DON'T have cell walls and thus our cells are NOT killed by the antibiotics (its easy to kill bacteria, but most things that would do this would affect your cells just as harshly) but when you get a bacteria that doesn't have a cell wall, you need an agent that attacks something that they actually DO have (but still something that we don't have)
 

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
Yes Thanks Justin, I actually do get that at this point!

I am more confused now about how this bacteria spreads.. The doctor tried to explain that it spreads differently then your bacteria with a cell wall. Somehow it moves from one place to another in a different method of transport sort of. I want to know how it spreads or multiplies? I think she said something about attaching itself to something rather then just replicating itself.. I guess it can't do that in the same way as a bacteria with a cell wall or something like that, so its carried or becomes attached to new organs or places to eat or thrive or something ...I am confused! Whats new!
 

Offline MayoFlyFarmer

  • Hero Member
  • *****
  • Posts: 863
    • View Profile
    • http://www.myspace.com/wiguyinmn
ohhhh.....  do you happen to know if this bacteria forms what is called a "bio film"?  has your dr. mentioned that term or have you seen it in your reading?  i don't reeally know all that many specifics about biofilms, but it sounds like what you're talking about.  i know they're supposedly very interesting from a scientific perspective, and a very hot area of research.  I actually had a very close friend who did her PhD reserach on trying to discover new antibiotics against bacteria that form biofilms.  Unfortunately,m she just finished up her PhD and moved on to do a Pot-doc somewhere else, so i couldn't ask her for info very easliy.
 

Offline Karen W.

  • Moderator
  • Naked Science Forum GOD!
  • *****
  • Posts: 31653
  • Thanked: 5 times
  • "come fly with me"
    • View Profile
So far she has found two and is testing for others. Mycoplasma Pneumoniae and another respiratory one called Chlamydia Pneumoniae. She said I have had this for a very long time and it has been reeking havoc inside, but she is rather evasive, well thats not the right word but she lacks the ability to explain things in terms I understand..

I honestly don't remember.. her explanation has a lot to be desired.. I have had to try to research it myself because I don't understand how it works. She said the antibiotics will treat it and it may become kind of dormant for awhile, then it will come back and we will have to do it again. It may take a long time.. But I am not sure .. Supposed to start treating it soon, like this week but have not had the finances to go back in and start treatment.... LOL.. soon I hope as I don't feel very good. I will look through the papers and see if I can find anything in them about that, but I am pretty sure she did not mention much more. I have been reading and it says I am contagious while I have this untreated which is not good but she did not tell me what to expect or anything else.. I asked her specificly to explain, but as of yet she just delayed treatment until I adjusted to a new heart med... Of which I ran out of and cannot afford.. LOL.. well Another delay it seems..

I will take a look and see what I find. Thanks Justin..
 

The Naked Scientists Forum


 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums