Science Buddies: "Ask an Expert"

Hi,

We (my 2nd grader and I) are working on the science experiment "Liver Stinks" and have a question about hydrogen peroxide and catalase. We understand that catalayse breaks down hydrogen peroxide in our body to water and oxygen, but why do we have hydrogen peroxide in our body? We've searched the internet and have found that hydrogen peroxide is a common byproduct of various metabolic processes but can't seem to find the answer to which processes? I'm trying to show my 2nd grader the relevance.

Thanks,
Giovanna Schroeter

Hi Giovanna,

I do apologize for the delay in responding to your inquiry. This is a great topic for a second grader.

Peroxide is produced from the metabolism or break down of amino acids and fatty acids from foods and occurs in the mitochrondia of cells. This is important for energy production in the cell. The enzymes that produce peroxide are called oxidases and there are always the catalase enzymes present to break down the peroxides.

Here is a short description of the biochemical process that results in hydrogen peroxide production:

http://www.madsci.org/posts/archives/19 ... .Bc.r.html

I'm sure you will be able to adapt this so your second grader will have an idea of what is happening.

Please let us know if you have any other questions.


Donna Hardy

Hi, I'd like to add to the previous comment. Hydrogen peroxide is a type of reactive oxygen species, and in addition to being produced during the breakdown of different molecules, it is also generated upon exposure to carcinogens like UV radiation and as a defense mechanism against invading bacteria. Reactive oxygen species can accumulate as you age, and they're a major reason why people get wrinkles and skin cancer after too much tanning.