Winter, J. Cell , — Article Google Scholar. Hong, W. Google Scholar. Ha, E. Science , — Download references. You can also search for this author in PubMed Google Scholar. Nature Reviews Microbiology. Ursula Jakob. Reprints and Permissions. Ledford, H. How does bleach bleach?. Nature Download citation. Published : 13 November Anyone you share the following link with will be able to read this content:.
Hsp33 also represents another example of an emerging concept in protein biology: that some proteins actually become activated through the act of partial unfolding. Indeed, chaperones react to stress by unfolding in the same way that other proteins do. Far from leaving them useless, however, that change in conformation is exactly what turns them on. As for whether the findings will have any practical implications, Jakob said she isn't yet sure. For instance, she has doubts that bleach could be made to work any more effectively than it does, particularly given that it works so rapidly and so well as it is even at low concentrations.
The findings in bacteria could perhaps offer new insight into the damaging effects of bleach on our own proteins, she added, noting that hypochlorous acid produced by the immune system has been suspected to play a role in chronic inflammation. But after wiping nonporous surfaces, you must be sure to let the bleach sit on the surface for 10 minutes or more to assure proper disinfection. Before using bleach, make sure the surface you are cleaning can handle a disinfectant. For example, bleach should not be used on wood floors or painted surfaces.
But bleach is fine to use on most kitchen counters, bathroom sinks, or even other frequently-touched surfaces such as door handles and faucets. To sanitize surfaces with unscented household bleach, the CDC recommends mixing together one cup of bleach and five gallons of water. Here's how to do it:. Air dry for at least 10 minutes.
Since this can result in toxic fumes, be aware of signs of over-exposure such as blurred vision, difficulty breathing, and headaches.
If you experience this, the CDC says to seek medical attention. For a smaller batch of cleaner, the CDC recommends using four teaspoons of bleach with one quart of water and following the same instructions. To sanitize fabric with bleach , add bleach to the wash cycle, then dry on high heat. The light that comes from the ketchup stain on your t-shirt to your retina has a wavelength of about nanometers, which makes it appear red [source: Atmospheric Science Data Center ]. The reason the ketchup stain reflects light with a wavelength of nanometers has to do with its chemical makeup.
Like most other substances, ketchup is made up of multiple elements joined together by chemical bonds to form molecules.
The electrons involved in some of these bonds are capable of absorbing light of certain wavelengths, depending on the characteristics of the chemical bond. The light that the electrons in a substance can't absorb determines the substance's color.
So the ketchup stain is absorbing all of the wavelengths of normal light that hit it -- except the nanometer light, which it reflects back to your eye, making it appear red.
Many stains have a network of double bonds between carbon atoms, and this network absorbs light. Chlorine bleach is able to oxidize many of these bonds, breaking them and taking away the substance's ability to absorb light. When this happens, the stain "disappears. It then appears white, like the rest of the shirt. The remains of the ketchup can still be there; you just won't see the stain anymore.
Soaking and washing the shirt can remove the now-invisible stain [source: Barrans ]. Since sodium hypochlorite is a powerful oxidizing agent, it is able to oxidize chemical bonds not only in stains on your clothing, but also in the dyes that give the clothing its color.
Anyone who has accidentally dripped chlorine bleach on their favorite pair of jeans has experienced just how effective bleach is as an oxidizing agent. A non-chlorine bleach that uses a weaker oxidizing agent, such as hydrogen peroxide, can break the chemical bonds in certain stains without breaking the stronger chemical bonds in clothing dye [source: Barrans ].
The use of chlorine bleach as a medical disinfectant was first recorded in Austria in Staff at the Vienna General Hospital began using it to keep "childbed fever," a severe infection that killed countless women after they gave birth, from spreading throughout the maternity ward [source: American Chemistry Council ].
The food processing industry uses chlorine bleach to kill hazardous bacteria such as Listeria , Salmonella and E. Sodium hypochlorite also is added to municipal drinking water to kill dangerous waterborne organisms like the bacterium Salmonella typhi , which causes typhoid fever and killed many people before water disinfection and antibiotic treatment became common [source: American Chemistry Council ]. Chlorine bleach kills Vibrio cholerae , the bacterium that causes cholera, a disease that killed in epidemic proportions before water treatment.
It can still kill in countries where clean drinking water is not available. Chlorine bleach can also kill dangerous bacteria and viruses on surfaces, such as methicillin-resistant Staphylococcus aureus MRSA , influenza and HIV.
Chlorine bleach is especially valuable as a disinfectant, since germs are not able to develop immunity against it, as they have done against certain drugs [source: Lenntech ]. To kill germs, sodium hypochlorite uses the same quality that makes it such a great stain remover -- its power as an oxidizing agent. When sodium hypochlorite comes in contact with viruses, bacteria, mold or fungi, it oxidizes molecules in the cells of the germs and kills them.
Scientists also believe that the hypochlorous acid that forms when sodium hypochlorite is added to water can break down the cell walls of some germs [source: Lenntech ]. The hypochlorous acid also seems to be able to cause certain proteins to build up in bacteria, making their cells unable to function [source: Winter ].
Non-chlorine bleaches that are oxidizing agents can also act as disinfectants on some surfaces, but they are less potent than chlorine bleach.
Chlorine bleach, when used properly, is a practical and effective disinfectant.
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