Why Some Sugars Have a Cyclic and a Chain Structure

Chemistry, Education
In your current course of organic chemistry, you're studying sugars. You notice in a text or see on the web a particular sugar, you've searched for by name. What is its true structure? You see it drawn as a chain structure with pendant groups. As you read about it, you see reference to another structure... a cyclic structure! What gives? Sugars: Example Fructose Some chemicals undergo change with the most minimal modification of environment. One example is keto-enol tautomerism. Fructose and certain other sugars experience something similar. It reacts reversibly, to form two cyclic hemiketals. Fructose Hemiketals A hemiketal forms by combination of an alcohol group with a ketone group. Fructose supplies both reactive groups, internally. For the generic reaction for hemiketal formation, see the accompanying illustration. Note the presence…
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Can Eating the Meat of a Rabid Animal Give You Rabies?

animals, Food
[caption id="attachment_25951" align="alignright" width="480"] Image by Scientific Animations CC BY-SA4.0[/caption] We're told to cook our chicken through to the bone to avoid salmonella. Then too, there is trichinosis. And there are others. However, salmonella and trichinosis pose no problem if, as we mentioned, we cook our food thoroughly. But there are other issues with food that are not so easily solved. For instance, there is the so-called "mad cow disease". You can cook the beef as much as you want and it still is dangerous! Mad cow disease is more officially known as bovine spongiform encephalopathy or BSE. Most of Us At least in the U.S., most of us probably get the bulk of our food from three sources: 1. Grocery store 2. Garden 3. Farmer's market A fair number…
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Earth Gravity – Distinguishing the Forest and Trees

Education, Physics
There's no point attempting to explain the precise nature of gravity here. Most of us are aware it is Earth gravity that enables us to remain standing on the planet. Gravitational force operates on all matter.¹ Is Matter the Same as Weight? No, the two are not the same. To illustrate, say a man is seated at the doctor's office and he is invited back. He is requested to stand on a scale. It says he weighs 210 lbs. We write w = 210 lbs. Now say that man is an astronaut. Ah! Next week he is deep in space. If he removes his restraints, he begins to float. He is weightless!² That is, w = 0 lbs. Yet his mass remains the same. That is, m ≠ 0. Weight…
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Carbide Cannons & Miners’ Lamps – The Chemistry?

Chemistry, Technology
When I was a kid, a friend showed me what he called an acetylene cannon. Many know it as a carbide cannon. What made it work? It's all a matter of chemistry. Which Carbide? A carbide is a compound in which carbon is bonded to a more electropositive element. Silicon carbide (SiC) and tungsten carbide (WC) are two well-known examples. What carbide do carbide cannons use? Calcium Carbide The answer is calcium carbide. Lime and coke are placed in an electric furnace. The chemical reaction is: CaO + 3 C → CaC2 + CO2↑ What makes calcium oxide so interesting is its bonding. The valence of calcium is +2. Ordinarily, carbon is assigned a valence of 4. Something's strange here... The puzzle is solved if we write the structure of…
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Artificial Butter Flavor – Just a Product of the Chem Lab?

Chemistry, Food
You are crunching away at some tasty munchable. Since you're not doing anything else and would like to prove you can do two things at once, you turn the bag/box around and read the ingredients. Yes, yes, oh that! And yes, yes, ah. What's that? Artificial Butter Flavor? What's artificial butter, the product of artificial cows? What Is Artificial Butter Flavor? Simply put, the expression "artificial butter" refers to taste and use, rather than to any single, particular ingredient. A Simple Compound Diacetyl is considered to impart a buttery flavor to foodstuffs. As the illustration shows, diacetyl is a small, simple molecule. Writing it out in full, it is... CH3(CO)(CO)CH3 Note the similarity to two acetic acid (vinegar) molecules... CH3(CO)–OH + HO–(OC)CH3 [sc name="MidArticleAdsense"] Synthesis The second image depicts one…
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Alkene Isomers and Nomenclature: 1,3,5-Hexatriene

Chemistry
Many moons ago, chemistry was divided into two large groups, organic chemistry and inorganic chemistry. Organic chemistry was thought to be the 'chemistry of life'. This was because a mysterious "vital force" associated with life was thought essential to produce organic compounds. Most organic compounds consist of carbon and hydrogen atoms, with or without nitrogen, oxygen, phosphorous, or other atoms. We will discuss a simple hydrocarbon. A hydrocarbon consists solely of carbon and hydrogen. Hydrocarbon Bonds Carbon and hydrogen usually bonds in one of three ways: single bonds (-), double bonds (=), and triple bonds (≡). In this article, we will feature only single and double carbon-to-carbon bonds... two single and three double. The compound is 1,3,5-hexatriene. Notice the featured image (above) that illustrates the most common way it is…
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Adenosine Triphosphate (ATP) and Metabolism

Chemistry
In discussing the chemistry of the human body, the media features many important substances. Take water. We are told how important it is to drink lots of water. Our body cells do consist, after all, of about 60% water. And we repeatedly hear of DNA, cholesterol, free radicals, omega fatty-acids, trans fat and sodium. Yet, there is one essential compound that is seldom mentioned... adenosine triphosphate, acronym ATP. Have you heard-tell of ATP? No? Yet it is remarkably important – you could not exist without it. Besides, even if you could, the energy you'd need to function would be totally unavailable. ATP - What Is It? ATP, on examination (see image) is one molecule consisting of three portions. There is an adenine portion attached to a ribose (sugar) portion, attached…
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Static Friction and Kinetic Friction AKA Sliding Friction

Education, Physics
You return home. You find that while you were gone, the UPS man dropped off a large cardboard box in front of your garage. The box is made of very thick cardboard. Clouds are rolling in. You need to put the box in the garage. But it's just you and the box is super-heavy. You have no alternative but to push it in. You Take Note You've had your coffee today, so you're on top of your game. Your mind is sharp as it will ever get. You position your hands and shove the box with everything you've got. You give it your best! Curiously once it starts, it isn't that hard to move, as long as you keep moving. You realize with that Sherlock Holmes brain of your that…
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Anodizing Aluminum: How Can It Be Done?

Astronomy, Chemistry, Technology
Aluminum is a versatile metal, yet in order to be used in certain applications, it needs to be modified, improved. One way of modifying it is to add certain ingredients, such as a trace of copper, to toughen it. Another modification is the process of anodizing aluminum. What does that refer to? Anode & Cathode We're all familiar with electroplating. We may have eaten meals using silver-plate utensils. Or we may have attended a classic auto show in which older cars have chrome-plated bumpers. A metal coating (plating) from a chemical bath is applied using electricity to transfer the metal from a supply source (the anode) to the object to be plated (the cathode). The simplified artwork below illustrates a copper bath, complete with anode, cathode, and plating solution. A…
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Explosives: Nitrogen-Containing Fulminates

Chemistry
Chemical explosives are unstable¹ solids (occasionally liquids) that decompose rapidly, releasing large quantities of gas. The sudden volume increase pushes violently against whatever contains the explosive, reducing it to shrapnel and releasing a thunderous noise. Many explosives are nitrogen-containing substances, such as trinitrotoluene (TNT), nitroglycerin, and the picrates. Additional historic explosives include the fulminates, and yes, fulminates contain nitrogen as well. The most famous fulminate is mercuric fulminate, officially named mercury(II) fulminate. Its chemical composition is, Hg(CNO)2 It consists of one mercury atom and two atoms each of carbon, nitrogen, and oxygen. In greater detail, it can be written, Hg+2(C≡N=O)2 or Hg+2(C≡N+–O-)2 Do Fulminates Remind You of Other Chemicals? Perhaps the anionic fulminate ion, –CNO- reminds you of the cyanate anion, –OCN- or isocyanate anion, –NCO? And well it should,…
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