honors ~ cellular respiration & photosytnesis 1213

Cellular Respiration

Honors Biology

http://www.science.smith.edu/departments/Biology/Bio231/etc.html

http://www.youtube.com/watch?v=3y1dO4nNaKY

Photosynthesis

Bacteriorhodopsin

“Tragedy of the gifted rugby player, 18, who died after buying deadly 'fat-burning' pills online,” the Daily Mail reports. It is just of

one of many newspapers and websites who have reported on the death of Chris Mapletoft, who died after taking 2,4-

Dinitrophenol (DNP). This is a banned substance that has been marketed on the

internet as a "wonder slimming aid".

DNP has also been linked with the deaths of students Sarmad Alladin and Sarah Houston

earlier in 2013.

http://www.youtube.com/watch?v=BBVnM9T5er8

• 2,4-Dinitrophenol (2,4-DNP, or simply DNP), C6H4N2O5, is an inhibitor of efficient energy (ATP) production in cells with mitochondria.

• Consider potential targets.

• Warning signs of DNP poisoning• Warning signs include:• hot dry skin • excessive thirst • excessive sweating • abnormally fast heartbeat • rapid breathing • In 1933, an American researcher discovered that when taken by humans, DNP

dramatically speeds up the metabolism leading to rapid weight loss. It was subsequently marketed as a weight loss drug. It was quickly withdrawn from the market, however, after it was found to be highly toxic, causing significant side effects and in some cases, deaths.

• In 1938 the American Food and Drug Agency issued a statement saying DNP was “extremely dangerous and not fit for human consumption”.

• It appears that DNP has becoming increasing popular during the last decade among bodybuilders for its "quick-fix" ability to lead to rapid weight loss. Presumably this information was spread both by word-of-mouth as well as via internet forums and message boards.

• It uncouples oxidative phosphorylation by carrying protons across the mitochondrial membrane, leading to a rapid consumption of energy without generation of ATP.

• Given your understanding of oxidative phosphorylation, how do you think this would drive weight loss?

• Pharmacological action

• In living cells, DNP acts as a proton ionophore, an agent that can shuttle protons (hydrogen cations) across biological membranes.

• Consider significance.

Mechanism:

•DNP uncouples oxidative phosphorylation by carrying protons across the mitochondrial membrane, leading to a rapid consumption of energy without generation of ATP.•It defeats the proton gradient across mitochondria and chloroplast membranes, collapsing the proton motive force that the cell uses to produce most of its ATP chemical energy. Instead of producing ATP, the energy of the proton gradient is lost as heat.