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You will learn about "Dalton's Atomic Theory" in this video. John Dalton was an English chemist who is very well known today for his work in the development of atomic theory. Let us learn the postulates of Dalton's atomic theory. All matter, whether an element, a compound or a mixture are made up of very tiny particles called atoms. All atoms of a given element are identical in size, mass and chemical properties. Atoms of different elements differ in size, mass and chemical properties. Atoms are indivisible particles which can neither be created nor destroyed in a chemical reaction. Atoms combine together in fixed whole number ratios to form compounds. In a chemical reaction, atoms only get rearranged. An atom of an element does not change into the atom of another element.

The complex systems of high school dating and chemical reactions may have more in common than you think. Explore five rules for speeding up chemical reactions in the lab that might just land you a date to a dance!

9:14 video Have you ever wondered how life first got started on Earth? So do scientists! Though the question has not yet been fully answered, a careful study of Chemical Evolution is beginning to shed light on this mystery. In this film you will learn what Chemical Evolution is, how it works, and how it is different from Biological Evolution.

This case study presents the story of "Nick," a student who has been assigned the task of writing a research paper describing the fundamentals of chemical bonds and how they relate to human life. When Nick experiences difficulty remembering information about the different types of chemical bonds, he turns to his tutor, Josh, for help. Josh explains orbitals and valence electrons to Nick, and then they together review nonpolar and polar covalent bonds, ionic bonds, and hydrogen bonds. A final practical application exercise requires that students write about how different types of chemical bonds may relate to the development of Alzheimer's disease and to the mechanism of action of potential drug treatments.  The case is presented with PowerPoint slides and is designed to be used with a personal response system ("clickers"), but students can instead record their answers on paper or share them verbally.  The content is appropriate for use in high school and undergraduate introductory chemistry and biology courses.

Panobinostat is a new type of drug that works by blocking an enzyme responsible for modifying DNA at the epigenetic level. Epigenetics refers to chemical marks on DNA itself or on the protein "spools" called histones that package DNA. These marks influence the activity of genes without changing the underlying sequence, essentially acting as volume knobs for genes. Earlier genomic studies showed that about 80 percent of DIPG tumors carry a mutation that alters a histone protein, resulting in changes to the way DNA is packaged and tagged with those chemical marks. This faulty epigenetic regulation results in activation of growth-promoting genes that should have been turned off, and shutdown of others that should have acted as brakes to cell multiplication. Cancer is the result. Panobinostat appears to work by restoring proper functioning of the cells' chemical tagging system.

IN recent weeks, two major medical organizations have issued independent warnings about toxic chemicals in products all around us. Unregulated substances, they say, are sometimes linked to breast and prostate cancer, genital deformities, obesity, diabetes and infertility. "Widespread exposure to toxic environmental chemicals threatens healthy human reproduction," the International Federation of Gynecology and Obstetrics warned in a landmark statement last month.

Bonnie Bassler discovered that bacteria "talk" to each other, using a chemical language that lets them coordinate defense and mount attacks. The find has stunning implications for medicine, industry -- and our understanding of ourselves. Bonnie Bassler studies how bacteria can communicate with one another, through chemical signals, to act as a unit. Her work could pave the way for new, more potent medicine.

A microbe that causes malaria tricks mosquitos into helping it spread, a new study finds. The microbe is a parasite that leaves a chemical behind in the blood of the people or other animals that it infects. Mosquitoes are drawn to scent of blood hosting this chemical. It entices them to slurp up some of the infected meal. Then voila! The parasites get airlifted from their old host to new ones. And so malaria spreads.

The Miller-Urey experiment was the first attempt to scientifically explore ideas about the origin of life. Stanley Miller simulated conditions thought be common on the ancient Earth. The purpose was to test the idea that the complex molecules of life (in this case, amino acids) could have arisen on our young planet through simple, natural chemical reactions. The experiment was a success in that amino acids, the building blocks of life, were produced during the simulation. The finding was so significant that it kick started an entirely new field of study: Prebiotic Chemistry. Scientists now have reason to believe that the gases used in the Miller-Urey simulation were not actually the same as those of the ancient atmosphere. Because of this, many experiments have since been done, testing a wide variety of atmospheres and different environmental conditions. The results are overwhelming: the molecules of life can form under a wide variety of ancient Earth-like conditions. Many questions about the origin of life remain to be answered but these findings give strong support to the idea that the first living cells on Earth may have emerged from natural chemical reactions.

This interrupted case study examines basic concepts of chemical bonding by telling the story of "Madison," a young girl eager to learn how her hair can transition from natural curls to straight, smooth tresses. The case can be used to teach or review the major categories of bonds (ionic, covalent and hydrogen), major macromolecules of life, and hydrolytic and dehydration reactions. It also explores how chemical relaxers and heat through blow drying and flat-ironing can change the nature of straight, wavy and curly hair through the disruption of protein shape. Students will thus learn what it means when a protein has become denatured and how various variables such as pH, heat and salts can lead to the unraveling of the three-dimensional shape of proteins. This case is suitable for an AP high school course, or for an introductory biology or chemistry course for majors or non-majors. This activity can also be used as a review of basic biology and chemistry for students in an upper-level biochemistry course.

Topic: Turgor Pressure Why does a touch me not plant close? Hey!! Don't touch that plant. You will get scared. See, you did not listen to me. Don't worry!! Nothing to be scared about. Let me tell you more about this plant. This plant is called the Mimosa Pudica plant. Another name for it is "Touch Me Not" Plant. When anyone touches this plant, it closes its leaves with the help of pulvini. Pulvini are present at the base of each leaflet. They consist of cells filled with water. This water applies pressure against the walls of the cells. This pressure is called the turgor pressure. It helps the leaflets to stand upright. Now, when we touch a leaflet of the touch me not plant, specific parts of the plant release certain chemicals. These chemicals cause the cells in the pulvini to lose water. When water is lost, there is no more turgor pressure. As a result, the cells collapse, resulting in the closing of leaflets.

" IBM scientists have been able to differentiate the chemical bonds in individual molecules for the first time using a technique known as noncontact atomic force microscopy (AFM)."

Published today (17:00BST, 03/06/2015) in the journal Neuron, their work presents strong evidence that disruption of a delicate chemical balance in the brain is heavily implicated in the disorder. In the largest ever study of its kind, the team found that disease-linked mutations disrupt specific sets of genes contributing to excitatory and inhibitory signalling, the balance of which plays a crucial role in healthy brain development and function.

Dubilier is hardly alone in her plight. A heaping teaspoon of soil or a shot of ocean water may contain as many as one million bacterial species. Many of them are potential gold mines of chemicals and metabolites with medicinal, engineering, and energy applications. But when researchers have tried to culture these microbes in the lab, only a minority of cells form colonies. Clearly, nutrients, a carbon source, and time are usually not enough to coax bacteria isolated from the wild to grow in a laboratory setting. So what's the missing ingredient?

7 minute video discusses electron cloud, electronegativity,  Good video, more appropriate for honors, chemistry, or AP.

Paul Andersen discusses scientific evidence of the origin of life on our planet. He begins with a brief discussion of the age of the earth and ends with the future of humanity. He includes geologic, chemical and molecular data.

Because the gene-enzyme system forms a closed loop, it presents us with a classic chicken or egg conundrum: Which came first, genes or the protein enzymes they code for? While the details are still not fully worked out, discoveries over the past few decades have lead researchers to a surprising possible solution: What really came first? Genes that act as enzymes! The RNA World Hypothesis is the idea that before living cells, the genetic code, and the gene/protein cycle ever existed, chains of a chemical called RNA were forming naturally. Once formed, some of these chains were able to function as enzymes, and were even able to evolve by making copies of themselves with slight, accidental modifications.

This directed case study follows two college roommates, Darrell and Anthony, who have just returned to school after winter vacation. They share that their ageing fathers are concerned about their declining faculties and are amused by their fathers' efforts to reverse the process.  Darrell's dad plays "brain games" on the computer while Anthony's father believes running will slow his memory decline. Intrigued, the roommates search through their biopsychology class notes to find out whether their fathers are correct. They review the topics of synaptic formation and plasticity, including axonal and dendritic development, and chemical factors in the brain that promote the survival and growth of neurons or stop the genetically programmed death of neurons. Based on research findings, students reading this case will decide whether Darrell and Anthony's fathers are correct in their assertions. The case is appropriate for a wide variety of courses including introductory anatomy or physiology, or for upper-division biopsychology, biology, or neuroscience courses.

In this video Paul Andersen explains how the electrochemical gradient is a combination of the chemical and electrical gradient of ions. As ions move across a membrane the potential change creates a hidden force that isn't always apparent.

Common in cuisine all around the globe, onions are renowned for their ability to make us all look like cry babies. In Reactions' latest video, we get to the bottom of this teary phenomenon and reveal exactly what chemical mechanisms trigger it. The video also features a few chemistry-backed tips you can try at home to stop the tears before they start.