[finchbeak]

But it's a nice surreal experience.

[David Sparkman]

Re temperature and bacteria

Most bacteria have chosen to have membranes and other internal constiutants made from chemicals that tend to break down at higher temperatures. They can break down by either crosslinking and becoming brittle, or by weak bonds coming apart and breaking down into smaller constituants.

Proteins tend to cross link. Try exposing a little avian ectoplasm to a mild amount of heat on your stove. I generally add some chopped onions and salt and pepper to my eggs (avian ectoplasm is a Yoke son, a yoke).

David

[biomed0101]

What about protein denaturation? One of the things happening to bacteria in boiling water seems to be denaturation of their proteins, much as the boiling of an egg. Is crosslinking also part of this denaturation process?

[]

[biomed0101]

quote:Proteins tend to cross link. Try exposing a little avian ectoplasm to a mild amount of heat on your stove. I generally add some chopped onions and salt and pepper to my eggs (avian ectoplasm is a Yoke son, a yoke).

Er, sorry, I read it too fast before I asked the question, it seems that you already answered it.

Isn´t this cross linking and becoming brittle the effect of higher kinetic motion of molecules? (sorry people, higher kinetic motion actually means molecules moving around faster), or is my idea on this subject flawed?

[]

[finchbeak]

biomed - you have the right idea, because "higher kinetic motion of molecules" is the definition of higher temperature.

[biomed0101]

Thank you finchbeak, and thank you on the comment describing the equation of state. You´re absolutely right pointing our attention on the relationship of P and T not being intricately depending on one another. Boy, the things that a layman forgets.
In the boiling water example, let´s follow what happens. First, the heat energy from the stove is conducted through the bottom of the pan, making the water molecules move around faster (as finchbeak explained, the water temperature rises), we can name this higher kinetic energy. Because of this higher kinetic energy, water can escape the pan in both gaseous and liquid form. This means that the amount of substance (in chemistry denoted as n) decreases. So, if we look at finchbeaks example above, n*R*T isn´t constant, in fact it decreases because of the variable n. Most pure substances, such as water tend to change from liquid into gaseous form at a constant temperature. for water, this is at T=373.2K(100 degrees centigrade). Now, look closely at the pan, it´s fully open to it´s surroundings, here you can conclude that the pressure must be equal to the atmosphere. There, P and T arent intricately related.
Now, if you put a lid on the pan, that doesn´t let out any gas, the kinetic energy of the water molecules bounce off at the walls with higher speeds. (correct me if I´m wrong) This means that in a given time interval of let´s say one second, more mass units bounce off at the same area than when at lower temperature, thus when we look at the mathematical definition of pressure, p=F/A, we might conclude that p has increased when heated. n didn´t change, because of the lid.

Now, I´m not really sure if this is correct, but I imagined it this way, with help of my textbooks.

[]

[gsmollin]

quote:Originally posted by Bin Laden

I give all my jihad children heavy water.

catch me if you can!

You are killing all of your jihad children.

"F = ma, E = mc^2, and you can't push a string."

[gsmollin]

Back on topic, I'm pretty sure it all comes down to pathogens in the water supply, and boiling used to be good advice, since it will kill most bacteria. However, it does not kill all protozoans, especially cryptosporidian oocysyts and sporozoites. These tough organisms are the ones most likely to escape a public super-chlorination system. To kill crypto, you should be using a special water filter. Here's a page about water filtration, and it has a link to the UK water inspectorate. Of course, they are selling, but crypto is the most serious water borne threat to the newborn.


http://www.1x1x1.co.uk/water/filtration/water_biology.htm

"F = ma, E = mc^2, and you can't push a string."

[neilep (OP)]

quote:Originally posted by gsmollin

However, it does not kill all protozoans, especially cryptosporidian oocysyts and sporozoites. These tough organisms are the ones most likely to escape a public super-chlorination system. To kill crypto, you should be using a special water filter. Here's a page about water filtration, and it has a link to the UK water inspectorate. Of course, they are selling, but crypto is the most serious water borne threat to the newborn.


http://www.1x1x1.co.uk/water/filtration/water_biology.htm



"F = ma, E = mc^2, and you can't push a string."

Thank you gsmollin, and the link is appreciated...however, I'm a dab hand with a pair of tweezers and a magnifying glass and I reckon I've got the cryptosporidian oocysyts and sporozoites under control !![]

Men are the same as women.... just inside out !!