What is Benedict's Reagent

Benedict's reagent is a chemical compound made up of copper sulfate, which can detect the presence of glucose or fructose. A reagent is a chemical that is applied to another substance in order to produce a chemical reaction that can give valuable information regarding the substance. Benedict's reagent is most commonly used to calculate ways of reducing glucose or fructose in foods. In the past, it was the way diabetes was detected through the testing of urine.

In food tests, a small amount of the food is added to Benedict's reagent and boiled for several minutes to test the amount of sugar present. The results will show precipitates, or solid formations within the tested substance. The amount to which a precipitate is present can show the exact glucose or fructose present in the substance. 

Since the precipitates are likely to be very small, Benedict's reagent also shows color changes that can gauge the amounts of the sugars glucose and fructose. For example, a substance treated with Benedict's reagent that is green shows very little or possibly no glucose or fructose present. On the other hand a red color indicates a high quantity of these sugars.

In people who are suspected of having diabetes, analysis of urine is one of the main diagnostic method. Pregnant women used to undergo an analysis of urine that was treated with Benedict's reagent to check for gestational diabetes. Today, other tests may be used because they are more precise in measuring sugar levels. 

Pregnant women may resent these frequent urine tests but they are in fact very important to rule out diabetic conditions during a pregnancy. Benedict’s reagent only works so far in diabetic testing however, since presence of fructose in the urine does not suggest a diabetic condition.

Thus, urine must be further tested, if it shows positive when mixed with Benedict's reagent to evaluate for the presence of glucose. For some, this may mean no further testing with Benedict's reagent, but drinking a glucose solution that most find quite distasteful. However, untreated diabetes should not go unchecked. Thus, diagnosis is extremely valuable and may help begin early treatment, which can significantly change later outcome.

What is a Wind Farm

A wind farm is a collection of windmills or turbines which are used to generate electrical power through their mechanical motions as they are pushed by the wind. Both Europe and the United States have large numbers of wind farms, and the technology is also found on other continents. In Asia, India especially has devoted a great deal of funding to establishing wind farms. The energy generated by a wind farm can be fed directly into the general energy grid after passing through transformers.

As a potentially large source of renewable energy, wind farms are particularly popular in nations which are focusing on alternative energy. Other types of renewable energy include wave power and solar arrays. All of these technologies take advantage of already existing energy, converting it into a usable form. Since a wind farm does not actively deplete resources as it generates power, it is considered a form of “green” energy.

Naturally, some resources must be expended to create a wind farm. The turbines, transformers, and grid system on a wind farm are often made from less than ideal substances, such as metals mined in an unclean way. However, once installed, a wind farm requires no additional energy output other than that required for basic maintenance. This is a marked contrast to a power plant which relies on coal or petroleum products. Consumers who want to support wind farms can buy energy credits which go to developers of wind farms.

Naturally, the best place for a wind farm is a windy location. In some instances, a windy location may also be generally unusable or uninhabitable. In other instances, a wind farm may take up useful real estate which could be used for farming. This has led to some criticism of wind farms, since they take up a great deal more space than a comparable non-renewable energy generating facility. In addition, wind farms pose a severe threat to migratory birds, as has been clearly documented by several scientific organizations.

These issues aside, the technology is generally believed to be environmentally sound and fiscally viable. Especially if wind farms are combined with other renewable energy sources, green energy could make up a bulk of the power grid. This could have a huge impact on the environment and on society in general. Especially at the end of the twentieth century, when a growing number of citizens began to call for energy reforms, wind farms held a great deal of promise.

What Is a BTU

BTU, short for British Thermal Unit, is a basic measure of thermal (heat) energy. One BTU is the amount of energy needed to heat one pound of water one degree Fahrenheit, measured at its heaviest point. In other words, if you placed 16 ounces of water at 59°F into a stovetop pan and turned on the gas burner, it would take one BTU to raise the temperature of the water to 60°F. As more BTUs continue to flow from the gas flame, the water will eventually reach the boiling point of 212°F. 

A BTU is also the equivalent of 252 heat calories, not to be confused with the kilo-calories of food, and of approximately a third of a watt-hour. When speaking of cooling power, the BTU also works in reverse. The air-cooling power of an air conditioning system refers to the amount of thermal energy removed from an area. Hence a 65,000 BTU heater and a 65,000 BTU air conditioner are of roughly the same capacity and size. The higher the BTU output, the more powerful the heating or cooling system.

Strangely enough, the British Thermal Unit is rarely used in Great Britain anymore, where it is considered a non-metric measurement. Even in countries which use the BTU as a standard measurement, there is some disagreement over the formula used to derive it. The thermal energy needed to raise water one degree Fahrenheit can depend on the original temperature and the method used for heating. Therefore, it is possible to get several different definitions of a BTU from different sources. This rarely has a palpable effect on consumer product information, however.

Most heating and cooling systems produce thousands of BTUs, almost rendering the measurement of one BTU pointless. One is more likely to encounter smaller BTU figures during scientific experiments, where the slightest change in thermal energy may need to be calculated in terms of calories. When dealing with central air conditioning units and commercial pizza ovens, however, the BTU numbers can easily reach the hundreds of thousands. A unit of measure called the MMBTU is the equivalent of a million BTUs. Few man-made objects can generate this level of thermal energy, however.

When shopping for heating or cooling systems, keep in mind that even the smallest window-mounted air conditioner or space heater can produce thousands of BTUs. The BTU numbers should primarily be used as a comparison between systems. Larger and more expensive systems should provide significantly higher BTUs than smaller ones. When deciding between similarly priced units, compare the BTUs for a better gauge of performance.

What are Organic Compounds

Organic compounds are the complex compounds of carbon. Because carbon atoms bond to one another easily, the basis of most organic compounds is comprised of carbon chains that vary in length and shape. Hydrogen, nitrogen, and oxygen atoms are the most common atoms that are generally attached to the carbon atoms. Each carbon atom has 4 as its valence number which increases the complexity of the compounds that are formed. Since carbon atoms are able to create double and triple bonds with other atoms, it further also raises the likelihood for variation in the molecular make-up of organic compounds.

All living things are composed of intricate systems of inorganic and organic compounds. For example, there are many kinds of organic compounds that are found in nature, such as hydrocarbons. Hydrocarbons are the molecules that are formed when carbon and hydrogen combine. They are not soluble in water and easily distribute. There are also aldehydes – the molecular association of a double-bonded oxygen molecule and a carbon atom. 

There are many classes of organic compounds. Originally, they were believed to come from living organisms only. However, in the mid-1800s, it became clear that they could also be created from simple inorganic proteins. Yet, many of the organic compounds are associated with basic processes of life, such as carbohydrates, proteins, nucleic acids, and lipids. 

Carbohydrates are hydrates of carbon and include sugars. They are quite numerous and fill a number of roles for living organisms. For example, carbohydrates are responsible for storing and transporting energy, maintaining the structure of plants and animals, and in helping the functioning of the immune system, blood clotting, and fertilization – to name just a few. 

Proteins are a class of organic compounds that are comprised of carbon, hydrogen, nitrogen, and oxygen. Proteins are soluble in water. The protein itself is composed of subunits called amino acids. There are 20 different amino acids found in nature – organisms can convert them from one to another for all but eight of the amino acids. 

Lipids comprise a class of organic compounds that are insoluble in water or other polar solvents; however, they are soluble in organic solvents. Lipids are made of carbon, hydrogen, oxygen, and a variable of other elements. Lipids store energy, protect internal organs, provide insulation in frigid temperatures, among other features. Lipids can be broken down into several groups ranging from triglycerides, steroids, waxes, and phospholipids. 

Nucleic acids are another group of organic compounds. They are universal in all living organisms. In fact, they are found in cells and viruses. Some people may not consider a virus to be a living thing. Friedrich Miescher discovered nucleic acids in 1871.

What is UV Light

UV light, short for ultraviolet light, is light with a wavelength shorter than that of visible light, but longer than X-rays. This means electromagnetic waves with a wavelength between 400 nm and 10 nm, with energies from 3 eV to 124 eV. UV light is more energetic than visible light and has a shorter wavelength, letting it penetrate more readily through obstacles. The "ultraviolet" in ultraviolet light references that UV light is beyond violet on the electromagnetic spectrum. Like other forms of electromagnetic radiation outside the visible spectrum, UV light is invisible, but it can be observed indirectly by the way it makes many other substances fluoresce in the visible spectrum. 

In popular culture, UV light is primarily thought of as a party light because of the way it makes textiles and clothing, particularly white shirts, fluoresce brightly. "Black lights" are synonymous with UV light. These lights primarily produce light in the UV portion of the spectrum, but they also produce a slight violet glow. Special posters or other works of art are often created with the express purpose of fluorescing a certain way under a black light. 

UV light has many other applications outside of the party scene. It is frequently used in security. For instance, sensitive documents, such as currency, driver's licenses, credit cards or passports, have invisible symbols on them that light up only in the presence of UV light. These are difficult for counterfeiters to copy.

Common fluorescent lamps are powered by UV light. UV light is produced by ionizing low-pressure mercury vapor, which is then absorbed by a special fluorescent coating, which in turn produces visible light. Fluorescent lights are more energy-efficient than conventional light bulbs. 

Biologists and zoologists are quite fond of UV light as it helps them take nighttime organism surveys in the field. Certain birds, reptiles, and insects (such as bees) are clearly visible under UV light, and quickly flashing a UV light over a small area can allow observers to count the approximate number of organisms of a given type in that area. This is very helpful because many animals are highly nocturnal and rarely if ever seen during the day. 

Besides the above mentioned applications, UV light can also be used for spectrophotometry (to analyze chemical structure), analyzing minerals, chemical markers, photochemotherapy (for psoraisis), very fine resolution photolithography, checking electrical insulation, sterilization, disinfecting drinking water, food processing, lasers, and many other areas.

What is Chromatography

Chromatography is a process which can be used to isolate the various components of a mixture. There are a number of different types of chromatography in use, including gas, liquid, paper, and gel permeation chromatography, and this process can get quite involved, especially with complex mixtures. It is also an extremely useful addition to a variety of fields, including pure and applied sciences, forensics, and athletics, among many others.

The process relies on the fact that different molecules will behave in different ways when they are dissolved in a solvent and moved across an absorbent medium. In a very simple example, one could take ink and make a mark on a piece of paper. The paper could be dipped into water, and the capillary action of the water would pull the ink through the paper. As the ink moved, its ingredients would separate out, revealing a distinctive pattern which could be used to determine the components of the ink.

In preparative chromatography, researchers separate individual components of a compound for use in the lab or in research. This process can get extremely precise: using a preparative chromatography technique, for example, a scientists can isolate two strands of DNA which differ by only a few pieces of information. In analytical chromatography, the goal is to figure out what is in a sample. Drug testing relies on analytical chromatography to isolate illicit substances in urine and blood samples, for instance.

In the example above with a dot of ink and a piece of paper, the basic concepts behind the process are illustrated, although most chromatography machines are a bit more sophisticated. It is important to choose the right solvent or carrier fluid to dissolve the sample in, and to select an appropriate solid medium to pass the sample through. Poor choices can result in confusing or inaccurate results, and the chromatography procedure requires substantial skills on the part of the operator to ensure that it returns useful data.

The result of a session is a chromatograph, a printout which provides information about the substance being analyzed. The printout usually takes the form of a chart with a series of troughs and peaks. Each peak represents a substance present in the sample, and the concentrations of these substances can be determined by looking at the height and width of the peak. Computerized chromatography machines generate such printouts automatically as the data is produced, and they can also be made by hand.

What Are Cilia

The term cilia is Latin for "eyelashes." Common in single-cell organisms, these hair-like structure wave to move the cell around or to move something around the cell. Cilia also are present on most cells in the human body. Some tissues in the body, such as the Fallopian tubes in women and the trachea, also have a special type of cilia that help transport substances along the tissues' surfaces.

Types of Cilia in the Body

In the body, cilia on the surface of tissues are responsible for protecting a person from germs in the lungs and for pushing an ovum through the Fallopian tube, among other tasks. These cilia are called motile cilia, and they are found in groups and beat in waves. Primary cilia, on the other hand, usually are found only one at a time on cells.

Structure

The structure of a single cilium is much like a tube, and its long fibers are called microtubules. These microtubules often pair up to form doublets, which in turn form a ring. The cross-section of doublets of microtubules looks like a figure 8, because the two microtubules stick together along a line. Nine doublets form the larger ring in what is known as a 9-2 pattern. When kinesin binds to one side of the doublets and not the other, the cilium flexes and curves, similar to the way a person's skeletal muscles contract. 

Functions

Single-celled eukaryotes, which are organisms with cells that have a nucleus, often use cilia to move through liquid. This type of organism is surrounded by a cytoskeleton, made of protein filaments that allow the cell to hold its shape. A cilium attaches to the cytoskeleton of the cell with a basal body, the way a root attaches hair to human skin. 

The rhythm of waving cilia is controlled by centrioles, which are organelles located inside the cell wall. Mitochondria, other units inside the cell, provide adenosine triphosphate (ATP), a source of cellular energy, for the cilia. The ATP directs the chemical kinesin to bind to certain parts of the cilia that control their movement. Thus, the cilia are able to beat or essentially swim their way through viscous liquid.

Flagella

Similar to cilia, flagella are longer such hairs, usually found in ones or twos, such as the tail of a sperm. They share many characteristics with cilia, but they also occur on prokaryotes, which are organisms with cells that do not contain a nucleus. Some eukaryotes that use cilia and flagella to move are also found in ferns, on algae, on bacteria and inside many animals. This adaptation originally allowed independent cellular creatures, such as paramecia, to move around in search of food, rather than wait until food came to them. Cells that are part of larger systems have continued to use cilia to their advantage.