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exactly what does soap do to bacteria?
Posted: January 17, 2003, 6:42 pm
by Adex_Xeda
If I were to put an amoeba under a microscope and watch it as I put soap in its presence, what would I see happen?
An inquiring mind wants to know.
Posted: January 17, 2003, 6:44 pm
by Lalanae
Pure soap? nothing. It would have to contain antimicrobials to do anything to bacteria. Things like Triclosan are antimicrobials.
Posted: January 17, 2003, 6:45 pm
by Adex_Xeda
Lets take old timey lye soap, if it didn't kill bacteria, what was its purpose?
Pardon me if I'm a little foggy in the brain today, but I can't seem to recall...
Posted: January 17, 2003, 6:47 pm
by kyoukan
Soap saturates itself with imbedded dirt and lifts it up off whatever it's attached to. It doesn't neccesarily kill bacteria but I'm sure there are some kinds that die from the chemical properties.
Posted: January 17, 2003, 6:48 pm
by Dalmoth
I remember salt 'n pepper in a dish then adding soap force all the salt 'n pepper to the edge of the dish. Had to do with the active ingredients being naturally repellant. Been 20 years since I've been in a chemistry class though.
If the single celled organism acts like a child it will curl up in the other end of the petri dish.
Posted: January 17, 2003, 6:48 pm
by Bubba Grizz
Soap creats a bond between the water and the oils on your body. So when you rinse off you lose those oils. Maybe they contain the bacteria we worry about.
Posted: January 17, 2003, 6:51 pm
by Lalanae
It removes dirt an oil from the skin, thats all. Bacteria usually resides there, but soap does not "kill" bacteria.
The problem with soaps are they are highly alkaline which means that they can damage the skin's acid mantle which actually helps protect the skin from bacteria. Detergent cleansers usually have a higher acidity (closer to the skins natural acidity) and therefore the acid mantle is preserved. Most liquid "soaps" are really detergent-based cleansers.
Be careful using anti-bacterial cleansers. Recent studies are showing that the increase of anti-bacterial use is making bacteria more resistant.
Posted: January 17, 2003, 6:57 pm
by Bubba Grizz
Actually soap makes the bacteria talk a bit cleaner. At least that is how it worked at my house when I was a kid.
*disclaimer* They will prolly swear behind your back anyhow.
Posted: January 17, 2003, 6:57 pm
by Lalanae
Interesting study that says anti-bacterial soaps don't work anyway.
http://cbc.ca/stories/2002/10/25/Consum ... ial_021025
Posted: January 17, 2003, 7:00 pm
by Voronwë
the trick is soap has to get wet.
think of wet soap molecules as like these tadpole looking things with 2 tails.
the tails go in the same direction and are basically molecular fat. as such they dont mix with water.
the round end of the tadpole mixes (dissolves) in water, so basically forms hydrogen bonds with water molecules (loose association of electric field).
the tails of the soap molecule are highly attracted to just about all organic molecules. most things we consider 'dirt' have at least some degree of organic molecules in them. food remains, basically anything of a biological nature will attract these tails when soap gets wet. mostly because the tails really dont mix with water at all, so they want to get next to things they do mix with (organic molecules).
so basically the end result is around organic molecules, and a bacterium would be a big bag of these, you will get as many soap molecules as are available in the local environment. tails sticking in, to touch the organic stuff, head sticking out forming a wall to interact with the water.
the common antibacterail agents in soaps act by just poking big holes in the plasma membranes of the bacteria if i recall correctly. it isnt stuff like penacillin that an organism can easily develope a resistance too. this would require it to reengineer its plasma membrane which is not trivial.
the thing bacteria has going for it is that it reproduces real fast, which means more genetic combination events, which lets it evolve at a fast rate.
Posted: January 17, 2003, 7:05 pm
by Lalanae
If I didn't already know how surfactants worked Vor, I would have no freaking clue what you just said....*boggle*
Posted: January 17, 2003, 7:12 pm
by Voronwë
man i was trying to make it straightforward too

Posted: January 17, 2003, 7:16 pm
by masteen
Soap does to dirt what Sparty does to rabbits. Is that more clear?
Posted: January 17, 2003, 7:23 pm
by Canelek
When I got a couple tatoos, I was told by the artist to only use Dial Anti-Bacterial to clean them 3 times a day. They never got infected which is cool, but I always wondered what was so different about the "anti-bacterial" label.
Then again, I probably can just compare the ingredient lists, but that would be far to simple.

Posted: January 17, 2003, 7:28 pm
by Metanis
masteen wrote:Soap does to dirt what Sparty does to rabbits. Is that more clear?
Nice turn of phrase

Posted: January 17, 2003, 7:59 pm
by Adex_Xeda
Thanks guys,
Posted: January 17, 2003, 9:43 pm
by Xaem
Soap is made from a fat and a number of chains of fatty acid - it is a lipid.
What it does when combined with water (the chains of fatty acid, like Voronwe said, the 'tadpole tails') is that it attempts to form H-bonds with several of the different type of bacterium (and water) in your skin - this pierces the plasma membrane of the bacterium and tries to break it loose from your skin.
Posted: January 22, 2003, 11:04 am
by Kylere
Voronwë wrote:the trick is soap has to get wet. BLAH BLAH BLAH BLAH BLAH
'Scuse me while I run and get a biology degree, then come back and reread this.
Posted: January 22, 2003, 11:39 am
by miir
Canelek wrote:When I got a couple tatoos, I was told by the artist to only use Dial Anti-Bacterial to clean them 3 times a day. They never got infected which is cool, but I always wondered what was so different about the "anti-bacterial" label.
From that link Lananae poted:
Larson says anti-microbials are good for preventing skin infections and several studies have proven that.
Makes sense to me.
Posted: January 22, 2003, 1:11 pm
by Chidoro
Voronwë wrote:the trick is soap has to get wet.
think of wet soap molecules as like these tadpole looking things with 2 tails.
the tails go in the same direction and are basically molecular fat. as such they dont mix with water.
the round end of the tadpole mixes (dissolves) in water, so basically forms hydrogen bonds with water molecules (loose association of electric field).
the tails of the soap molecule are highly attracted to just about all organic molecules. most things we consider 'dirt' have at least some degree of organic molecules in them. food remains, basically anything of a biological nature will attract these tails when soap gets wet. mostly because the tails really dont mix with water at all, so they want to get next to things they do mix with (organic molecules).
so basically the end result is around organic molecules, and a bacterium would be a big bag of these, you will get as many soap molecules as are available in the local environment. tails sticking in, to touch the organic stuff, head sticking out forming a wall to interact with the water.
the common antibacterail agents in soaps act by just poking big holes in the plasma membranes of the bacteria if i recall correctly. it isnt stuff like penacillin that an organism can easily develope a resistance too. this would require it to reengineer its plasma membrane which is not trivial.
the thing bacteria has going for it is that it reproduces real fast, which means more genetic combination events, which lets it evolve at a fast rate.
Jesus. What the hell do you do for CNN?
Posted: January 22, 2003, 1:29 pm
by Animalor
He explains to the anchors wtf everything they're talking about is.
Posted: January 22, 2003, 2:11 pm
by Kilmoll the Sexy
He is quite obviously the washroom attendant.
Posted: January 22, 2003, 2:23 pm
by Voronwë
my job is to post on messageboards.
Posted: January 22, 2003, 2:27 pm
by Pilsburry
So you go in the bathroom with dirty hands, you open the door, you poop, wipe, turn on the water, wash your hands.
Then you touch the faucet again to turn the water off, the one you touched with your dirty hands, and then you open the door up that you touched with your dirty hands...and now your back at square one..time to go wash your hands.
Actually aren'tbacteria on the skin one of our defenses against illness?
I hate to play devils advocate talking about hygene in one thread and not being overly anal about washing your hands in another...wait no I don't, I love it.
Posted: January 22, 2003, 3:49 pm
by Lalanae
Not all bacteria is bad. The ones you need to be worried about are the ones that spread illness (colds & stuff), the ones that come from poo & pee, and the ones that come from raw meat. Those are the only ones that will have some kind of negative effect on you. People that sanitize their hands 15 times a day are just weakening their skin's natural defenses.
Posted: January 22, 2003, 3:55 pm
by Voronwë
i disagree. washing your hands is an extremely effective way to prevent communicable disease transmission.
typically infections do not happen due to skin contact. it is when the virus/bacteria contacts a mucous membrane (eyes, mouth, nose, ears, naughty bits). so if you have influenza virus partcles on your hand and you pick your nose, rub your eye, try to get something out of your teeth, you are potentially exposing yourself to disease.
i have never heard of any sort of beneficial bacteria on your skin that effectively work as part of an immune response. they may exist, but i've never heard of them. i'm not a doctor

.
i recommend cleaning your keyboard regularly as well. those things are disgusting after awhile.
you do have to keep the bacterial crop that grows in your gut happy though. otherwise it is full steam ahead out of the poop shoot!
Posted: January 22, 2003, 4:07 pm
by Lalanae