Thursday, May 4, 2017

Salting out and Salting In






Salting Out and Salting In


Salting out is a purification method that uses reduced solubility of certain molecules in a solution with a very high ionic strength. Salting out occurs in aqueous solutions that have a very high ionic strength. Salting out is typically used for the precipitation of large biomolecules such as proteins. The large biomolecules are typically controlled with hydrophobic and hydrophilic interactions with the cell's environment. In the aqueous solution that has a very strong ionic strength, the water molecules surround the charges of the ions and proteins. When the aqueous solution reaches a certain strength, the water molecules are no longer able to support the charges of both the ions and proteins. This results in the precipitation of the least soluble solute.Salting out occurs in an aqueous solution of high ionic strength that reduces the solubility while salting in increases the solubility by adding more salt. “The solubility of a protein at low ion concentrations increases as salt is added”, basically increasing its solubility, is known as salting in. In Salting in when salt is added the protein’s solubility at a low ion concentration increases. Also when the salt is added, it adds additional ion shields to the proteins multiple ionic charges. This causes the attractive forces to weaken between other proteins. An example of salting out purpose is to separate the glycerin from the soap. The contents of the kettle salt out into an upper layer that is a mass of impure soap and underneath that is the aqueous salt solution with the dissolved glycerin.

 Resources:

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Wednesday, May 3, 2017

Radiation (Nuclear Chemistry)



                When most people think of radiation, they think of mushroom clouds, nuclear reactors, and x-rays. While radiation does include the aforementioned examples, it encompasses a much broader list of things. In physics the term radiation is broadly defined as, energy in the form of waves or certain particles, such as those that make up alpha radiation. There are two main categories of radiation, non-ionizing radiation and Ionizing radiation. The main difference between the two are their ability to harm living organisms.
Ionization by removal of electron
                 As stated by it’s the name, ionizing radiation is form of radiation that has the energy capable of making ions. This type of radiation mainly includes the higher frequencies of ultraviolet light, x-rays, alpha particles, beta particles, and gamma rays. For these to create ions, they must collide with atoms or molecules in turn depositing its energy, either  causing bonds to break or causing the movement or removal of electrons. This form of radiation is evidently very dangerous as it can possibly interact with strands  
Dose (in mrem)

Effect 
25,000 to 100,000
Temporary blood changes
100,000
Double the normal incidence of wogenetic defects
100,000 to 200,000
Vomiting, diarrhea, reduction in infection resistance, possible bone growth retardation in children
200,000 to 300,000
Serious radiation sickness, nausea
300,000 to 400,000
Bone marrow and intestine destruction
400,000 to 1 million

Acute illness and early death (usually within days)
of DNA. These effects come in two different categories, threshold effects and non-threshold effect. As shown by the chart on the left, threshold effects occur when the radiation dosage reaches a certain point. And the effects cannot apply to any dosage below the threshold. Conversely, non-threshold effects are able to occur at low levels of radiation. The most observed effect under this category is cancer. Though cancer can occur with low doses, it is much more likely with increasing levels of exposure.
The subcategory of non-ionizing radiation, as compared to its counterpart, ranges greatly from sound waves and gravitational waves to microwaves, infrared and visible light, and the lower energy frequencies of ultraviolet light. These are categorized together as they do not have enough energy to ionize matter. All of these are mostly not recognized by the general public as radiation, but they are in use in many of our everyday appliances such as microwaves, WiFi, radios, and the visible spectrum of light which causes color to be perceived.
Another type of non-ionizing radiation that I did not name is blackbody radiation, and these are very interesting for multiple reasons. Firstly, a blackbody is an object that can theoretically absorb and release all frequencies of radiation. Since the ideal blackbody should absorb all radiation, it should be black as the name suggests. A blackbody in practice though will not stay completely black though as absorbing high amounts of radiation should cause the object to glow. A blackbody should theoretically be able to release all types of radiation, categorized as blackbody radiation, but in application most blackbodies will only emit thermal energy, which is what causes the glow. The exceptions to this rule are black holes. These are the one and only blackbody that will emit the full spectrum of radiation. This works because of particles and antiparticles such as electrons and positrons, muons and animuons, etc. Theoretically, throughout the universe particle-antiparticle pairs are created spontaneously, but we cannot observe them as they instantly annihilate each other. Because the pairs are thought to only exist for instants they can neither be confirmed or denied, deeming it the title of theory as a consequence of the Heisenberg Uncertainty Principal. This all changes however if a particle pair is created near the event horizon of a black hole. As shown by the image above, when a pair is created near the horizon, it is possible for one particle to pass over while the other is able to escape. This therefore is able to create radiation while removing some mass from the black hole, showing that black holes can decay and eventually completely evaporate.                                                                                                                                                                                      Sources:
http://www.nj.gov/dep/rpp/llrw/download/fact07.pdf
https://www.nrc.gov/reading-rm/basic-ref/glossary/radiation-ionizing.html
http://www.radiationanswers.org/index.html
http://www.ehrs.upenn.edu/programs/radiation/nonionizing_faq.html
http://astronomy.swin.edu.au/cosmos/B/Blackbody+Radiation
https://www.universetoday.com/40856/hawking-radiation/
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3D Bioprinting [Biochemistry]

3D printing is a very familiar concept to most people, the definition of it is to make a physical object from a three-dimensional digital model by laying down many thin layers of the given material. As the technology advances, 3D printing now has more usage in many different areas, the materials can be used to do the printing also expand. Bioprinting is one of the innovations in 3D printing, it uses the printing technology to produce usable tissue of human body for medical purpose.
The idea of bioprinting originated in 2002, Professor Makoto Nakamura realized that the droplets of ink in a standard printer are about the same size as human cells. By 2008, he has created a working bioprinter that can print tubes similar to blood vessels. The bioprinter created in 2008 has three print heads, two of which print cardiac and endothelial cells, the other one print “bio-paper” that support the cells during printing. Most bioprinters have the similar function to support the cells during printing, some produce a dissolvable gel to support and protect cells during printing. The material used in 3D printing does not always have to be actual living cells, in can be just materials that incorporate with human cells so it can be accepted by the human body. In fact, researchers in University of California use C6H12O6 as the bioprinting material, it acts as a filament that will be covered with cells. It is a perfect material that is not toxic to the human body and will keep its structure as it hit air temperature.

Although most 3D bioprinting is in its experimental state, there is some recent success. In March of 2017, researchers from Sahlgrenska Academy and the Chalmers University of Technology had printed structure made from human cartilage cells on the backs of live mice. In May, the team of researchers at Sahlgrenska Academy has managed to generate cartilage tissue without the use of mice testing. The team used cartilage cells harvested from patients who underwent knee surgery, and the cells were rejuvenated into stem cells, which have the potential to develop into many different types of cells. The stem cells were then expanded in the composition of cellulose that put into the 3d bioprinter and printed into the wanted structure. Following the printing, growth factor was add that caused the structure to differentiate correctly in order to form cartilage tissue.

The fact that stem cells survive going through the process of 3D printing is a success by itself. Due to the fact that it can be manipulated into different types of cells, with the right growth factor and structure, functioning tissue or even organs can be printed. And it can be used in organ transplant, patients will no longer need to wait for an organ donor, but printed their own organ with their body tissue. 3D printing is already playing its role in the medical world right now, it creates a more natural cell interaction than the traditional 2D method, with better predictable value and higher clinical relevance. It also helps speed up drug development, improves the safety and efficiency. 3D printed cells also relief the experiment on inhumane animal testing.
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Nuclear Imaging

Nuclear Imaging

There are many forms of nuclear imaging. There is the PET Scan, Thallium Scan, Gallium Scan, and SPECT. This form of nuclear medicine uses radioactive materials to detect, diagnose, and diseases. These procedures allow for a person to not undergo surgery to see what is inside or to deliver therapy. In the procedures, scientists choose an isotope that would occupy the brain at the time necessary to show the function of the brain. The half-life of the isotope is very important to take into consideration. The goal is to find or supply therapy to certain parts of the body without disrupting any of its functions.
PET Scan also is known as Positron Emission tomography helps by diagnosing, staging, and monitoring treatment of certain kinds of cancer. A PET neuroimaging can early diagnose Alzheimer’s which helps to distinguish between it from dementia. A PET Scan produce 3D images in high resolution. A commonly used tracer is 18 Fluoro 2 Deoxyglucose. The glucose will be absorbed by cells in the same manner as regular glucose would. Once absorbed the glucose goes through phosphorylation and stays inside of the cell. The now phosphorylated molecule is unstable and breaks down. The phosphorylated molecule releases a proton and two photons. The unit camera that produces the 3D image detects those photons. The Thallium Scan is used to study the blood flow to the heart muscle. The procedure uses traces of the radioactive of thallium which spreads through the heart muscle. It also includes the usage of gamma cameras to track the movement of the tracers through the heart muscle. The Gallium Scan uses radioactive nuclide. It is used by injecting the substance into the veins of the patient. That tracer travels through the bloodstream and collects where there is an accumulation of white blood cells. The accumulation of white blood cells means there is inflammation in the body tissue. It takes the images two-three days after the injection. SPECT is also known as single photon emission computed tomography. This scan is used to image tumors and infections. The procedure also studies the blood flow in the tissue.

 Resources:
https://chem.libretexts.org/Core/Physical_and_Theoretical_Chemistry/Nuclear_Chemistry/Applications_of_Nuclear_Chemistry/Application%3A_Radiation_in_Biology_and_Medicine/Case_Study%3A_Nuclear_Imaging

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[Nuclear Chemistry] Nuclear Energy

   What is Nuclear Energy?
   Nuclear Energy is the nuclear reactions that makes the nuclear energy releases to generate heat which used in steam turbines and produced electricity in a nuclear power plant. Nuclear power plant absorb uranium atoms is called fusion. Nuclear energy can contribute to reduce the need for fossil fuels now used for electricity generation. Every coin has two sides, negative and positive, this is also link to our topic, Nuclear Energy. It gives energy to electricity but also makes radioactive. There were some accidents that the large amounts of radioactive could be released into the environment which causes the health. Some of the disasters of nuclear power plant could be seen in Chernobyl (Ukraine) and Fukushima (Japan).

   What is "Fukushima Daiichi" nuclear disaster?
   Firstly, let's figure out the "Fukushima Daiichi nuclear disaster" in Japan, which initiated primarily by the tsunami following the Tōhoku earthquake on 11 March 2011. Fukushima Daiichi is 250 kilometers northeast from Tokyo. The tsunami wave arrived less than an hour after the earthquake and as high as 10 meters hit the power plant. The wave went over the seawall flooding the lower parts of buildings and disabled the emergency diesel generators on the reactors, which means the the operator was unable to reactivate the heat exchanger and the core was no longer cooled. The active reactors automatically shut down their sustained fission reactions. There were caused three nuclear meltdowns, hydrogen-air chemical explosions which occurred in Unit 1,3,4 and caused structural damage. The water level went down and the the temperature continued to rise all three safety measures had failed. The result is that there was over 20,000 people dead or missing destroyed towns ports and lands devastated.

This is the video that helps you to understand more about the "Fukushima Daiichi nuclear disaster:

   What is "Chernobyl disaster"?
  Secondly, the Chernobyl disaster was the most disastrous single nuclear accident in history took place on April 26 1986. Each Chernobyl reactor was capable of producing 1000 MW of power. A reactor is a big cattle filled with water, it emits radiation, the radiation heats the water, the steam now turns the turbines and it's generator produces electricity. One day, the Chernobyl engineers want to know what happened to the turbine if a reactor was slowly shut down. When they started the experience by low the temperature to the lowest level, the large amounts of steam, heat and radiation started to escape into the atmosphere. The reactor made the situation even worse. As the fuel rods ignited they started to melt forcing their way through the large water module. The Chernobyl disaster released up to 30,000 roentgens into atmosphere. It resulted 237 people suffered from the acute radiation sickness, 31 died in only 3 weeks and more than 135,000 people were evacuated from the danger area.

This video is talked about:"How the Chernobyl happened?", and here is the link: Resources:
http://www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/fukushima-accident.aspx

http://www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/chernobyl-accident.aspx
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Tuesday, May 2, 2017

[Biochemistry] Enzymes

What is "Enzymes"?
    Enzymes are proteins that break down the food particles that we eat everyday and form energy. There are many different types of enzymes, for examples, the only enzyme that occurs in the stomach is pepsin which digests proteins such as: meat, vegetable, fruit and many others daily things. If the food we eat is cooked over 118 degree F, it destroys all the enzymes that naturally occur in the food.

   Specially, enzymes act as catalysts and substrates. Each enzyme can only bind to one type of substrate, for example, only glucose can fit to the glycogen active site because they have a right shape. The shape of the enzymes which fits to the other puzzle pieces of enzymes is called active site which splits the substrate. In the stomach, protein digesting enzymes break down bonds and hold the amino acid. The digested protein goes to the small intestine and save energy for supporting our body. The undigested fats in the protein goes too the old intestine and automatically goes out. Fats are digested in the small intestine by the lipase enzyme. For example, glucose protein, that we usually found in the products made from flour, is digested to absorb into a body, it is used up as energy but if it was too much, it will be combined together by special enzymes to form glycogen which is saved to use into another part of bodies. This model of enzyme action is called the lock-and-key model.    Without enzymes, these reactions would take place too slowly to keep our bodies alive. For example, in daily day, we need to eat 3 meals which are breakfast (the most important) then lunch and dinner. If you eat well diet, it is produced fats which help to form energy and support others proteins pumping blood to the brain. When you stop burning fats, you end up damaging your brain. Therefore, enzymes can just only act on one type of molecule. One more fun fact about enzymes is that they are recycled. Only a small amount of enzyme is needed to speed up thousands of reactions.


The optimal pH for enzymes is almost neutral (about 7.3 to 7.4) and it can cause changes in protein structure and shape. For example in the picture below that represented the situation which show the two different enzymes might have two different pH optimal. The green line can represent the glucose protein and the red line can be the pepsin protein.

   Now a day, cancer is the leading cause of death not only in the United States but also in many countries all around the world. Therefore, many scientists want to find the way to end it. In 2006, a group of scientists t Children's Hospital Oakland Research Institute (CHORI) identifies a specific enzyme that can cause the death of cancer cells. Researchers studied the behavior of an enzyme called sphingosine phosphate lyase (SPL), which can regulate cell growth and death by lowering the levels of a natural, growth-promoting lipid called sphingosine-1-phosphate, or S1P. One of the scientists called Dr.Saba said:"Although we're beginning our studies in colon cancer, we believe our research findings will have a direct impact on investigations for other cancers, including pediatric cancers. It is premature to suggest that SPL is the answer to curing cancer, but our research findings should dramatically advance our search for a cure". This experiment has not been used widely but still a big step in medicine for cancer.

References:
Modern Chemistry textbook
https://www.sciencedaily.com/releases/2006/11/061120182022.htm
https://ghr.nlm.nih.gov/primer/howgeneswork/protein

Video:
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Bio- Pesticide

Pesticide are toxic substances that are intentionally released into the environment to kill or control the population of a certain animals or plants that are classified as a pest. Some of the common pesticide types include herbicides which is use to kill weed, insecticides which is use to kill insect, fungicides which is use to kill fungus, rodenticides which is use to kill rodent etc. As a result, pesticide is not limited to agricultural use because it is also use at homes, parks, school, forest, roads and building to get rid of the pest that disturb human activities.
A recent article that is posted on April 26, 2017 stated that there a high rate of bees colony collapsing in the world. The main reason that cause the collapse and decrease in honeybee population is because there an increase in the number of farmer that use neonicotinoids, which is a type of pesticide that is under the branch of insecticides. This toxic chemical is more harmful toward invertebrate and insect than toward mammals such as birds and other bigger organism. The active ingredient that are use to produce neonicotinoids are acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiacloprid and thiamethoxam. According to UC San Diego, neonicotinoids chemical are commonly use on corn, soybeans and cotton. The problem of using this insecticide is that it not only kill pest but also kill honeybee (Apis mellifera) that helps to pollinate crops. When honeybees come in contact with neonicotinoids it will fly faster and longer than normal but after several day of being exposed to this chemical their flying speed and flying distance will be reduced by half. Beside this factor, it also impact the honeybees ability to look for nectar, find their way home, to reproduce and locate flowers. As a result, it is harder for honeybees to find food to support its colony because the negative impact decrease their foraging area by nearly 80 percent. Due to this reason, 28 percent of the 2.6 million honeybee colonies in America died last winter. The decrease in the number of honeybees have a huge affect on agriculture because according to U.S. Department of Agriculture each year honey bee pollinate about $15 billion worth of crops.
The reason why this pesticide is commonly used by farmer is because it is soluble in water, it metabolized overtime and it is a systemic insecticide, which means the plant can absorb the chemical. The way that the plant absorb the neonicotinoids into the body is through the metabolic process because the metabolism is responsible for breaking down the molecule that enter the plant body to keep the plant alive. But instead the resulting particles that breakdown from the Neonictinoid are toxic chemical. Due to this reason, the plant will become toxic for pest and honeybee because the toxic chemical will spread and enter the cell of the plant. The reason why this pesticide is soluble in water is because water and the ingredients use are all polar and this follow the theory "like dissolve like". Polar is when the charge on the molecule are unevenly distributed, which will cause one side of the molecule to be more negative. The toxic chemical that is absorb by the plant will enter all the tissue and cell in the plant so when pests come in contact with the plant, they will die from being poison. Out of all the chemicals in the table below clothianidin, dinotefuran, imidacloprid and thiamethoxam are most toxic for bees, while acetamiprid and thiacloprid have a moderate toxic level. Table 3.1 also show the half-life of each main active ingredient in Neonicotinoids. Half-life is the time required for half of the radioactive nuclide to decay. This show that the active ingredient that take the longest time to decay is Clothianjdin because it have a half-life of 148-1,155 days in the soil, while the active ingredient that decay in the shortest amount of time is acetamiprid because it have a half-life of 1-8 days in the soil.
The way that this toxic chemical kill pest and honeybee is by sending the toxic to their central nervous system. This will disrupt the function of there immune and nervous system and cause them to die. The only different between honeybee and pest is that honeybees doesn’t die straight away because it depend on the concentration of the toxic chemical inside there body. Due to this reason, they need to consume sufficient amount of toxic into their body in order to die. If they expose to 220ppm they will instantly but if they expose to 2-20ppm they will die within several weeks. Neonicotinoids can enter honeybee body through ingesting or when they come in contact with pollen and nectar of plant that obtain this chemical.
In conclusion, Neonicotinoids play a very important role in the agriculture industry because it is use by farmer to kill pest that disturb the growth of plant and sometime even kill them. Moreover, the use of insecticide also help prosper the amount of healthy crops being harvest. Even though Neonicotinoids is a very important insecticide it should not be use any longer because it not only decrease the population of honeybee but it also affect other valuable animals that live in agriculture land.

If you want to learn more about the affect of Neonicotinoids on honeybee or other animals please watch the video below.
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