E2science

Chemical formula:
Mg(OH)₂

Also known as milk of magnesia, magnesium hydrate, and brucite (mineral form).

Magnesium hydroxide is a naturally occurring chemical which has a number of medicinal and industrial uses. Industrially, it is an environmentally friendly and relatively safe-to-handle alkali (most alkalis are very caustic) used to control pH levels in wastewater treatment (having a pH of 9.5-10.5 as an aqueous solution). It can also be found in a number of consumer products as a flame retardant, fuel-oil additive, drying agent in food, clarifier in sugar refining, and an additive in toothpaste.

Medically it is most often used as an over the counter laxative or an antacid. As an antacid, its medical and industrial purposes are similar. As a laxative, it works by drawing water into the bowel from surrounding body tissue, softening and moisturizing waste to help it pass through the system.

Magnesium hydroxide should be stored in a tightly closed container away from direct light, heat, and moisture (not in a bathroom). Typical adult dosages as an antacid are 5-15ml or 650mg. As a laxitive: 2.4-4.8g or 30-60ml daily. Do not use any laxative for extended periods of time, as laxative dependancy may develop. To overdose requires very large amounts and is unlikely to be serious except in the most extreme cases. Check for possible drug interactions or conflicts with existing health problems before using.

In its pure form, magnesium hydroxide is a white solid or powder with a melting point of 350°C (662°F, 623K) and a density of 2.4x10³kg/m³. As a medicine is it usually mixed with other ingredients to create a pill or a liquid suspension (shake well before using, it doesn't dissolve well).

A materials safety data sheet for magnesium hydroxide is available at:
http://ptcl.chem.ox.ac.uk/MSDS/MA/magnesium_hydroxide.html

Sources:
http://mineral.galleries.com/minerals/oxides/brucite/brucite.htm
http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a601073.html
http://www.vitacost.com/science/hn/Drug/Magnesium_Hydroxide.htm
http://www.magspecialties.com/wtrbroch.htm
http://en.wikipedia.org/wiki/Magnesium_hydroxide
http://www.nationalmssociety.org/Meds-MagnesiumHydroxide.asp
http://www.wholehealthmd.com/refshelf/drugs_view/1,1524,417,00.html
http://books.nap.edu/books/0309070473/html/131.htm

Also known as:
L-phenylalanine
beta-phenylalanine
alpha-aminohydrocinnamic acid
(S)-2-amino-3- phenylpropanoic acid
alpha-amino-beta-phenylpropionic acid
Abbreviated as Phe or F

Chemical formula:
C₉H₁₁NO₂

Structural formula:
     H        H                      
      \      /                       
       C == C      H    H      O     
      /      \     |    |     //     
H -- C        C -- C -- C -- C -- O  
      \\    //     |    |          \ 
       C -- C      H    N           H
      /      \         / \           
     H        H       H   H          
(Based on original ASCII art from Tyrosine by jafuser)

L-phenylalanine, or just phenylalanine, is one of the essential amino acids that the body cannot produce on its own, it needs to be ingested as food. Being an amino acid, phenylalanine is found in foods high in protein. It has however been artificially isolated and can be found as an ingredient in other products, such as dietary supplements and the artificial sweetener aspartame (phenylalanine makes up 50% of aspartame).

Phenylalanine is processed by an enzyme called phenylalanine hydroxylase into tyrosine, which is in turn used to make neurotransmitters such as dopamine and norepinephrine. There is a very rare genetic disorder called Phenylketonuria (PKU) which causes a lack of the phenylalanine hydroxylase enzyme. Phenylketonuric individuals must follow a special low protein diet to limit their phenylalanine intake because their bodies cannot process it, instead allowing it to build up in the blood stream as phenylpyruvic acid, which results in a number of mental and physical disorders. Aspartame sweeteners, sold under brand names such as Equal and NutriSweet, are very popular in diet products. Due to their high levels of phenylalanine, these products are required by the FDA to bear the warning Phenylketonurics: contains phenylalanine.

The stereoisomer (molecular three-dimensional mirror image) of L-phenylalanine (the version discussed above) is D-phenylalanine. D-phenylalanine is not naturally occurring but can be synthesized in a laboratory and is used as a nutritional supplement.

Sources:
http://www.ess.sunysb.edu/tracy/whatis.html
http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/lph_0201.shtml
http://www.lef.org/protocols/prtcl-089.shtml
http://en.wikipedia.org/wiki/Phenylalanine
http://www.sweetpoison.com/phenylalanine.html

Also known as:
triolamine
Alkanolamine 244
Nitrilotriethanol
TEA
TEA (amino alcohol)
TEOA
Tris(b -hydroxyethyl)amine
Tris(2-hydroxyethyl)amine

Chemical formula:
(HOCH₂CH₂)₃N

Structural formula:

                    H
                   /
              H   O
               \ /
            H   C--H
             \ /
      H  H    C--H
      |  |   / 
H--O--C--C--N   
      |  |   \ 
      H  H    C--H
             / \
            H   C--H
               / \
              H   O
                   \
                    H

Other properties:
Melting Point: 18-21° C (64-70° F)
Boiling Point: 190-193° C (374-379° F)
Specific Gravity: 1.124
Flash Point: 185° C (365° F) (flammable)
Autoignition temperature: 315° C (600° F)

Triethanolamine is a common ingredient in skin lotion, eye gels, moisturizers, shampoos, shaving foams, cosmetics, laundry liquid, and many other products which come into contact with skin. It is caustic and is used in low concentrations as a pH balancer (to counteract ingredients which raise acidity) and emulsifier.

Exposure to higher concentrations can cause reactions, including contact dermatitis. Since it is a caustic irritant, contact with the eyes and mucus membranes is to be avoided.

Industrially, triethanolamine is used as a corrosion inhibitor, a vulcanization accelerator for rubber, and an admixture for concrete which accelerates the drying and hardening process (usually to counteract other admixtures which retard the drying process).

As an organic chemical, triethanolamine is readily biodegradable.

Related chemicals: Monoethanolamine (MEA) and Diethanolamine (DEA)

Sources:
http://www.dermaxime.com/triethanolamine.htm
http://www.inchem.org/documents/iarc/vol77/77-10.html
http://www.chem.unep.ch/irptc/sids/OECDSIDS/102716.htm
http://www.nchz.sk/en/PRODUCTS/ORG/triet.htm
http://www.bio-pac.com/biopac/ingred.htm
http://physchem.ox.ac.uk/MSDS/TR/triethanolamine.html
http://www.basf.de/en/produkte/chemikalien/interm/amine/eoa/applications/?id=V00-pn_D54n35bsf.dW

Chemiosmosis is one of the processes a cell uses to extract energy from food. It is the final step of cellular respiration (hereafter referred to as glucose for simplicity) in many multicellular organisms, humans included. After glycolysis and the Krebs cycle break down glucose into smaller organic compounds with minimal net gain in energy, the electron transport chain establishes a proton gradient. The proton gradient's potential energy is converted into kinetic energy which facilitates ATP synthesis. This conversion is the process of chemiosmosis.

. . . What?

The best way to grok chemiosmosis is through analogy. Consider an altitudinous mountain. A river flows freely from the top of this mountain to its bottom, thanks to gravity's persistent help. Now build a dam somewhere along this river. This dam will have (say) a hundred little openings through which water passes. In each of these openings is a wheel. As water flows through an opening, the wheel spins. The wheel's spinning can help us do work, such as grind wheat into flour. Eventually, without some sort of outside help, the river will run out of water. So once in a while it rains on the top of the mountain, glaciers melt, aliens refill the supply, or whatever. Keep in mind the primary goal of the dam is to grind wheat into flour.

As it turns out, chemiosmosis is a very similar process. The mountain is analogous to a mitochondrion -- a microscopic organelle that every animal cell owns. The mitochondrion is the center for nearly the entire process of cellular respiration. The mitochondrion's purpose is to convert food (glucose) and ADP into energy-rich ATP and waste (H₂O and CO₂). The mitochondrion is split into two parts by a membrane: an outer compartment and an inner compartment. In our example, the outer compartment would be everything above the dam, and the inner compartment would be everything below the dam. The dam itself is the membrane, which is creatively named the "inner membrane." The outer membrane of the mitochondrion is what separates it from everything else in the cell; we can safely disregard it for didactic purposes.

The river's water ultimately comes from rain, glaciers, or whatever it was you decided. This is when the electron transport chain (ETC) has a part. The ETC produces the "river water" of chemiosmosis: it places H⁺ ions in the outer compartment of the mitochondrion (above the dam) and OH^- ions in the inner compartment (below the dam). For the chemically illiterate, H⁺ and OH^- combine to form H₂O which is actually a waste product of this process. The inner membrane (the dam) is impermeable to both H⁺ and OH^- (just like water cannot go through the concrete dam). As everybody who is anybody knows, opposites attract. So the H⁺ and OH^- ions would really prefer there to be no dam in their way. They would even go so far as to spin wheels to meet up with one another. Inside each of the little openings in the mitochondrion is an F0F1 particle (the wheel). This F0F1 particle is an enzyme that catalyzes the synthesis of ATP. As the H⁺ ion goes through the F0F1 particle, energy is harvested which is used to produce ATP. The OH^- ions do not pass through the F0F1 particle.

What would happen if not everything went according to plan? What if H⁺ and OH^- ions could freely pass through the inner membrane? Think what would happen if water could permeate the dam's walls. Sure, some energy might be produced, but you would simply be wasting your time. What would happen if the "river water" were not replenished? Disruptions in the electron transport chain (which are what poisons usually do) would cause chemiosmosis to all but stop. If chemiosmosis stops, the organism would run out of ATP, which is necessary to nearly every bodily function, and die.

Peter Mitchell described the process of chemiosmosis in 1961 and subsequently won the 1978 Nobel Prize in Chemistry .

---

Sources:
My AP Biology class
Campbell, Neil; Reece, Jane; and Mitchell, Lawrence. Biology. 5th ed. Menlo Park, CA: Addison Wesley Longman, Inc., 1999.
I developed this analogy independently but I have come to find out that it is of course not original. Some other sources (however incredible) use this analogy very briefly such as http://www.biology.lsu.edu/webfac/dlongstreth/biol12014f02/lecture_12.htm

A salt made up of an acid and a base. The acid in phthalate salts is phthalic acid.

Phthalates such as the plasticiser di(2-ethylhexyl)phthalate (DEHP) are the chemicals that makes plastics like PVC bend. They are also used in conjunction with dyes to color textiles. They are used in cosmetics and shampoo. As a humectant, they act to retain humidity, in their role as an emollient they soften and soothe the skin. During some, but not all, medical procedures, especially those using PVC tubes, there can be a higher exposure to DEHP.

Phthalates are implicated in causing problems to the sperm production of males, causing infertility and maybe causing cancer by making the cells in the testicles forget their sexual inclination and purpose.

This is because phthalates resemble the female sexual hormone estrogen. The problem is exacerbated by the fact that during the pregnancy, a male foetus is usually protected from the mother's estrogen, however, it is not protected from the phthalates, causing a severe shortage of sperms, because some cells receive signals to behave like female cells, not like male cells. This is extremely bad because it happens so early and has consequences for the whole life, because whole groups of cells might fail to grow into their function as sexual organs or makers of sperms.

However, there are also other chemicals like DDT and PCB which could be a cause of these health problems. The chemical industrial complex has set up a .org web site named after phthalates which claims that everything is fine and that only lab rats have problems, not lab monkeys.

Will our society go into decline just as the roman empire, which had similar problems with lead poisioning? The Romans where not only using aqueducts to carry water, but also lead pipes. In fact, they also put lead in dyes and cosmetics.

Unlike for DDT where the threat is commonly accepted, the severity of the risk is unknown and I would be happy to update this node if it turns out to be low. Also, unfortunately I didn't turn up a structural formula for estrogen to compare the chemical structure by eye. A review by a NIH panel in July 2000 found that DEHP gives rise to concern. The defenders of phthalates that I saw often relied on documents from 1997 or earlier.

Sources:
FDA http://www.fda.gov/cdrh/safety/dehp.html provided by Doyle.
Lead info by yclept.