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Introduction So far, we have seen many presentations on chemical reactions and how they work, balance, and are the key to creating new compounds. Now that we have a good idea about all this, it is time to apply these concepts to our lives and take a look into the importance of chemical reactions and how scientists are using them currently to make new discoveries and inventions.
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IN THE NEWS TODAY Created By: Naomi Stambaugh + Greg Egan
NASA Scientists Discover A Chemical Reaction That Better Predicts Smog A research team at NASA has discovered a key chemical reaction that plays a big part in creating ozone, which although is an important part of our atmosphere, is a harmful air pollutant on ground level, called smog. By learning this new reaction, scientists can now predict air quality, regulate emissions, and estimate the health impact of air pollution more precisely.
How they did it! The key reaction the researchers are studying is between nitrogen dioxide and the hydroxyl radical. In sunlight, these compounds play a part in creating ozone, which on ground level is a harmful air pollutant to plants and animals. Until recently, scientists thought that they only combined to form nitric acid, which is thought to slow ozone creation. They also suspected a second reaction, which would make peroxynitrous acid, a barely stable compound that falls apart quickly, releasing the nitrogen dioxide and the hydroxyl radical so they can resume ozone creation. But up until now scientists didn’t know how quickly these reactions occurred and how much nitric acid was created compared to peroxynitrous, that was until JPL team at NASA built a high-accuracy advanced chemical reactor. The researchers found that these compounds don’t go away as fast as they thought because they discovered that not as much of it combines into nitric acid, therefore, now that they know the correct ratios they can predict more precisely the amount of smog being created. ^ This shows how the hydoxyl Radical and nitrogen dioxide React to form both nitric acid And peroxynitrous acid
DO YOU REMEMBER! The Question: What were the two compounds that combined to form both nitric acid, which slows down ozone production, as well as peroxynitrous acid, which increases the creation of smog? A Hydrogen dinitride and the oxyl radical B. Hydrogen dioxide and the nitride radical C. Nitrogen dioxide and the hydroxyl radical D. I didn’t pay attention because I’m a loser
A New Chemical Reaction Is Discovered For DNA Production Researchers have discovered a new chemical reaction that produces one of the four nucleotides, which are the building blocks of DNA. This reaction is unique because it includes an unusual first step, as well as unlike the other reactions that produce nucleotides, it uses an enzyme to speed it up. This is a great discovery, because with it’s help scientists may someday learn to create and even to decode DNA.
What This Means… The chemical reaction the researchers discovered uses a special enzyme: flavin-dependent thymidylate synthase, or FDTS. This enzyme is coded by the ThyX gene, and has been found in bacteria and viruses, including human ones, including biological warfare weapons. Before the discovery of FDTS, scientists thought thymidylate synthase, or TS was the main catalyzing enzyme in the creation of the DNA building block called deoxy-thymidine monophosphate. But now they know that both TS and FDTS complete a key step in the making of the building block. How it works is both these enzymes add a methyl group (which is one carbon atom attached to three hydrogen atoms) to the building block's main molecule called deoxy-uridine monophosphate, or dUMP. Learning that FDTS plays a part in the creating of one of the building blocks of DNA is a significant and important discovery because in the future scientist may be able to use this knowledge for the development of new antibacterial and antiviral drugs.
DO YOU REMEMBER PART 2 Why was FDTS important in the creation of one of the DNA building blocks? What did it act as in the chemical reaction? • A reactant • A product • An enzyme • A solvent • Something for the scientists to juggle, play catch with, and then eat as they waited for the reaction to happen
Researchers Record Ultrafast Chemical Reactions Through Vibrational Echoes Until recently, scientists were unable to watch ultrafast chemical reactions. But researchers from the University of Michigan have just discovered a way to observe these quick reactions. They came up with the idea to record these chemical reactions through the vibrations they produce. It is a very significant thing that we can now observe these ultrafast reactions because they offer a remarkable insight into the understanding natural and artificial charge transfer reactions, which are fundamental in processes ranging from cellular respiration to solar energy conversion.
How It Works Until now, researchers were unable to record these ultrafast chemical reactions because they faced many difficulties. First of all, in order to record them visually it would have required a camera with a shutter speed of femtoseconds. A femtosecond is the time it takes light to travel the length of a bacterium, or about one hundredth the width of a human hair. Also, only a few special molecules were privileged to be in the first solvent shell, the one scientists could monitor. Lastly, even with the few molecules they could monitor, they were not able to identify specifically the molecular species of the chemicals reacting. But now, they are able to record these chemical reactions because of a breakthrough. The key breakthrough was realizing that electrons move during chemical reactions, and that when the nearest solvent molecules sense the electron redistribution, their vibrational frequencies change. Therefore, we can monitor these reactions by recording the vibrational echoes produced by the reaction. Now that we can record these ultrafast chemical reactions, researchers can learn about and study them more exactly than ever before.
DO YOU REMEMBER PART 3 The reason it took until now for scientists to be able to record the ultrafast chemicals reactions is because they faced multiple difficulties. All of the following were obstacles they faced, except for which two? • Only a few special molecules were privileged to be in the first solvent shell, the one scientists studied • Electrons move during chemical reactions, so when the nearest solvent molecules sense the electron redistribution, their vibrational frequencies change • They were not able to identify specifically the molecular species of the particles they were monitoring • They needed a camera with a shutter speed of femtoseconds • They had no problems, the only reason they couldn’t monitor them until now was because they spent 4.2 trillion dollars attempting to create ice cream that scoops itself, and then the president was mad because the self scooping ice cream only came in vanilla and he liked chocolate so he wouldn’t give them any more money to buy equipment so they had to raise it themselves by washing people’s mustaches.
Conclusion Now we have learned the significance of chemical reactions, and how researchers use them to make important discoveries about the world we live in. We have seen many examples of chemical reactions in the news today, and have learned how scientists use them to help predict smog, create a building block of DNA, and, with vibrational echoes, study ultrafast charge transfer reactions. We hope you enjoyed this presentation, and now understand the importance of chemical reactions in our daily lives. Thanks For Watching!
FURTHER LEARNING!!! Next time you watch to the news, use a computer, or listen the radio, see if you can find examples of chemical reactions in the world today!
Articles http://www.sciencedaily.com/releases/2009/04/090416161133.htm DNA STORY http://www.jpl.nasa.gov/news/news.cfm?release=2010-356 SMOG STORY http://www.sciencedaily.com/releases/2010/09/100901121522 VIBRATIONS STORY
