Lead in Chocolate???

This week in bio inorganic, we were assigned to look through a series of topics and report on one we found interesting. I chose to talk about chocolate for no other reason than it is the best sweet treat in the world. When I began reading, I was quite surprised to find that the topic was about lead contamination in chocolate. This is apparently becoming a problem, being most prevalent in Mexican chocolate. The reason this is so, is because chili and tamarind are often used in Mexican chocolates, and these two particular "flavor additives" are grown in lead rich soil. The chili peppers are then dried, and this further concentrates the lead that was absorbed during the growing process. All of the articles that I read stressed that the lead poisoning in children is most concerning. This is because it takes a lot less lead to affect children than it does adults, and also because most of the poisoned chocolate is marketed toward children, such as in halloween candy. Lead poisoning mainly affects the nervous system, and the side affects range anywhere from depression, to forgetfulness, to hypertension. From what I have gathered, this is an ever-growing problem, and something needs to be done to help reverse it. Here are some pics of "lead lines" in the x-rays of children. The one on the left is of a three year old and the other is of a five year old.

-The High School Chemist

Sources
-http://www.faculty.virginia.edu/metals/cases/sheehan1.html
-http://www.associatedcontent.com/article/1166899/lead_contamination_in_chocolate.html?cat=5
-http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1459956/

Methane Monooxygenase

This week in Bio Inorganic, we were assigned to write on a metalloenzyme that we were assigned to research a week or two ago. The enzyme that I was assigned was methane monooxygenase (I'm going to call it MM). This enzyme catalyzes the formation of methanol, which is the first key state in the oxidative metabolism of methane. In more simple terms, MM helps turn CH4 into CH3OH. This enzyme is also capable of oxidizing the C-H bond of other alkanes. MM is found in methanotrophic bacteria, which metabolize methane as their only source of carbon and energy. These bacteria play a key role in cycling carbon in anaerobic systems. There are two types of MM: soluble, which contains an iron center bridged by an oxygen (Fe-O-Fe), and particulate, which utilized copper as its center. The particulate MM is poorly understood, and there is much more research to be done on this type. Each Fe in MM has a six coordinate octahedral environment. The oxidation state of the iron is III or II depending on which part of the reaction it is in. The spin state goes from 5/2 to 2, which is also dependent on the step of the reaction. The ligands are mostly O based with one N based ligand on each of the Fe. The resting, oxidized, and reduced structures of MM can be seen by following the first link. If you follow the second link, you can view the catalytic cycle and mechanism of MM.

-The High School Chemist

Sources
- http://en.wikipedia.org/wiki/File:MMOstates.JPG
- http://en.wikipedia.org/wiki/File:MMOcycle.JPG
- http://en.wikipedia.org/wiki/Methane_monooxygenase

Celestite

This week in Bio Inorganic, we were assigned to find a bio mineral that contained a metal other than Fe, Ca, of Si, and inform our classmates on the mineral. I chose to report on Celestite (Strontium Sulfate). Celestium is believed to have metaphysical properties such as clarity of mind, clear communication skills, balancing energies, and calming capabilities. This mineral is also thought to be excellent for use in dream recall and astral travel. That was the extent that I looked into those uses on account of they seemed a bit coo coo to me. Not so much the energy part, but the astral travel. Anyway, back on topic. Because Celestitie is made of strontium sulfate, it can be used as an ore/source of strontium. Only trace amount of strontium are found in the human body, but recent studies have shown that strontium is similar to calcium in that they absorb into human bone in a similar manner. This discovery has lead to the making of strontium supplements, and these supplements have significantly increased bone mineral density. Strontium, however, has a benefit that calcium does not. While both calcium and strontium inhibit bone resorption, strontium simultaneously stimulates bone growth. No other natural substance or drug is known to provide this dual effect. There is still research going on for strontium because not all of the biological harms and benefits are known about this element. Dr. Mullins found some cool pictures of this crystal for me, and if you would like to see them, just follow the first link below.

-The High School Chemist

-http://hyperphysics.phy-astr.gsu.edu/hbase/geophys/celestite.html

-http://www.algaecal.com/strontium.html