Recombinant DNA technology

In the past several years, the advent of recombinant DNA technology was seen as a revolution of biotechnology. Recombinant DNA, also known as rDNA, is an artificial type of DNA which formed by combining two or more sequences and strands of DNA that would not occur together usually. rDNA is sometimes called genetic engineering. The applications of recombinant DNA technology are widely used and increasing recently for various kinds of purposes for example, expand the potential of microorganisms, to produce natural proteins manufacture of vaccines or enzymes. Recombinant DNA is made by three common ways which included the transformation, phage introduction and non-bacterial transformation. Transformation is the step of inserting the interest DNA into a vector and then cut that piece of DNA with a restricted enzyme and then insert the DNA into the vector with DNA Ligase. After that the vector is inserted to a host cell like E. coli. The phage introduction is the process of transfection, which can be said as an equivalent of transformation but instead of using bacteria, a phage is used. This process uses lambda or other phages to produce phage plaques which contain recombinant. In non-bacterial transformation, a process which very is similar to transformation never use bacterial for the host. In microinjection, the DNA is injected directly into the nucleus of the cell being transformed while in biolistics, the host cells are bombarded with high velocity of microprojectiles. This technique was discovered by Peter Lobban and A. Dale Kaiser in Stanford University.

An overview of rDNA procedures
First of all, the vector should be isolated from an organism such as bacterium. Then the interest gene is inserted into that particular vector. The vector that chosen must be a self-replicating type of vector. As the interest gene was inserted into the vector, its taken up by a cell for example a bacterium. The cell is become transformed bacterium and the recombinant vector is grown to form many copies of clone of that vector. After finished cloning, the cells may isolated by the researchers to use for many purposes. One of the process that might undergo by the cloned cells is inserted into an organism to express in it and produce protein as the product. Moreover, a succeed of production of a rDNA needs some tools or techniques. Restriction enzymes are one of the tools. It is a special class of DNA-cutting enzyme which can recognizes and cuts or even digest one particular sequence of interest DNA. ( For example BamHI, EcorRI, HaeIII and HindIII ). As we know DNA is appear in double stranded and these enzymes cut both strands of DNA and produce blunt ends and staggered cuts which is not directly opposite each other. These ends can used to join two pieces of DNA and these sticky ends stretches single DNA by complementary base pairing.

Besides, vectors are another tools which used in rDNA technology. Vectors is seen as a vehicle for the replication of interest DNA sequences. It needs to be able for self replicating and to be a size for manipulated outside the cell along the rDNA process. Smaller vectors are easier to be manipulated which is not fragile when compare to the larger one. Shuttle vectors which are plasmids that exist in various species can be used to move cloned DNA among organisms. One of the techniques in rDNA is Polymerase Chain Reaction (PCR). This process is used to amplify the size of samples and it is used to increase the amount of DNA into large enough for research in a short period. Firstly, every strand of target or interest DNA will be the template for DNA synthesis. Four nucleotides, enzymes for catalyzing purposes and DNA polymerase is added to this DNA to form a new DNA. Primers (short pieces of nucleic acid) is added too to enhance the reaction start. The primers are complementary to the interest DNA and it will hybridize to make the DNA amplified. Now is the time for the polymerase to synthesis new strands which are complementary. Finally, the DNA is heated to convert the new DNA into single strands.

What Are the Benefits of Recombinant DNA Technology?

One breakthrough in recombinant DNA technology was the manufacture of biosynthetic "human" insulin, which was the first medicine made through recombinant DNA technology ever to be approved by the FDA. Insulin was the ideal candidate because it is a relatively simple protein and was therefore relatively easy to copy, as well as being extensively used to the extent that if researchers could prove that biosynthetic "human" insulin was safe and effective, the technology would be accepted as such, and would open opportunities for other products to be made in this fashion.

The specific gene sequence, or oligonucleuotide , that codes for insulin production in humans was introduced to a sample colony of E.coli (the bacteria found in the human intestine). Only about 1 out of 106 bacteria picks up the sequence. However, because the lifecycle is only about 30 minutes for E. coli, this limitation is not problematic, and in a 24-hour period, there may be billions of E. coli that are coded with the DNA sequences needed to induce insulin production. However, a sampling of initial reaction showed that Humulin was greeted more as a technological rather than a medical breakthrough, and that this sentiment was building even before the drug reached pharmacies. Ultimately, widespread consumer adoption of biosynthetic "human" insulin did not occur until the manufacturers removed highly-purified animal insulin from the market, thereby leaving consumers with no other alternative to synthetic varieties.

Recombinant cells are produced by inserting foreign genes into genetic code, or DNA. The process of recombination involves a vector, or gene carrier, that is inserted into a host cell. From this process, a variety of DNA technologies have been developed. The benefits of recombinant DNA include improvements in;

Cancer Research:
Through analyzing the genetic differences between normal cells and cancer cells, scientists are attempting to learn which genes are responsible for the uncontrolled growth of cancerous cells, as well as the ways in which these genes are activated or inactivated. According to geneticist Dr. James Frieson, it is possible to regulate a cell´s production of proteins by splicing portions of genetic code that affect that cell´s regulatory functions. If this method could be applied to cancerous cells through recombinant DNA technology, it may be able to halt uncontrolled cell growth.


Fertility:
Recombinant DNA technology is used to produce hormones for women with fertility issues. Recombinant human follicle stimulating hormone (r-hFSH), recombinant luteinizing hormone (r-hLH) and recombinant human chorionic gonadotropin (r-hCG) are all hormones that facilitate the proper functioning of ovulation and follicular maturation necessary for fertilization to become a success. As opposed to earlier methods of hormone production, recombinant DNA technology will bring about a higher efficacy, easier access and safer, less invasive infertility treatments.

Vaccines:
Recombinant DNA is used in vaccines that involve the direct injection of genetic material into the human body. This genetic material is in the form of a plasmid, or loop of DNA, from the foreign antigen that is the target of the vaccination. After it is injected through our muscle tissue, our cells take in the DNA and begin to produce the foreign proteins encoded in the plasmids. These proteins promote our bodies´ immune responses to the targeted antigen. DNA vaccinations could become less costly to produce, are potentially safer and are theoretically longer lasting than alternative forms of vaccinations.

Diabetes Treatment:
Recombinant DNA can be used to treat a variety of other diseases and conditions. The production of insulin through recombinant DNA technology has been especially effective for treating diabetes patients. Today, scientists are able to create human insulin that is identical to pancreatic insulin, thereby leading to the the safest and purest forms of insulin on the market.

Food Recombinant:
DNA has a role in food production for a number of plant and animal products. For crops, recombinant DNA has been used to create increased resistance to viruses/pests, more resilience in the face of harsh environmental conditions and added convenience for packaging and shipping. An example for use with animals is bovine somatotropin (bST), a hormone that can be bacterially inserted in dairy cows in order to increase milk production.


References:
1. Colowick, S. P.; Kapian, O. N. (1980). Methods in Enzymology - Volume 68; Recombinant DNA. Academic Press.
2. Tortora, Funke, Case. 2010. Biotechnology and Recombinant DNA. (10th edition). Pearson Education, Inc. Pg 247-270

Chemistry in Ink

An ink is a liquid containing various pigments and dyes used for coloring a surface to produce an image, text or design. Ink is used for drawing and writing with a pen, brush or quiill. Ink is a complex medium composed of solvents, pigments, dyes, resins, lubricants, solubilizers, surfactants, particulate matter, flourescsers.


Dye-based inks are generally much stronger than pigment-based inks and can produce much more color of a given dentsity per unit of mass. However, because dyes are dissolved in the liquid phase, they have a tendency to soak into paper.


Cellulose, the material that paper is made of, is naturally charged, and so a compound that complexes with both the dye and the paper's surface will aid retention at the surface. Such compound in common use in ink-jet printing inks is polyvinyl pyrrolidone.


An additional advantage of dye-based ink systems is that the dye molecules interact chemically with other ink ingredients. Because dyes get their color from the interaction of electrons in their molecules, the way in which the electrons can move is determined by the charge and extent of electron delocalization in the other ink ingredients. The color emerges as a function of the light energy that falls on the dye.





References

~"A History of Technology and Invention", by Maurice Audin
~Martin-Gil J, Ramos-Sanchez MC " Chemical composition of a fountain pen ink", Journal of Chemical Education

Sweating

Sweating is also known as perspiration, transpiration or even diaphoresis. It is secreted by the sweat gland under the skin of the mammals. It mostly consists of water and dissolved substances. Sweat contains various kinds of chemicals such as odorants(2-methylphenol and 4-methylphenol) as well as little amount of urea. The purpose of sweating is mainly to regulate the body temperature or thermoregulation. Sweating can achieve the goal of regulating the body temperature by evaporation from the skin surfaces because it has a cooling result due to the latent heat of evaporation of water. If a body move rapidly or doing exercises, sweating will be promoted due to the increase of metabolic rate and vice versa. The volume of water lost in sweat daily is highly variable, ranging from 100 to 8,000 mL/day. Sweat mainly contains of water and also minerals(like sodium, calcium, magnesium,and potassium) or even urea. Also many kinds of trace elements excreted along in the sweat such as iron, chromium, nickle and lead. The different circumstances of the internal environment will vary different composition of the sweat.

Sweating can be embarrassing, mostly because of the odor or smell came along with it, and nobody like to move around with wet clothes. However sweating should be nothing to get embarrassed about it. Usually men sweat more than women and most people would like to never sweat again. They willing to spend their money to buying up various kinds of antiperspirants, deodorants or body sprays. In fact, these should be avoided at all cost because these articles can block the pores in the skin sweat can causing cannot release the harmful toxins. Most of the deodorants contain aluminum which can makes its way into our bloodstream and eventually causing many diseases. Sweating should never be stopped because it helps to eliminate harmful toxins from the body and cleans the pores in the skin, thus helping to reduce black heads and acne. One of the advantages is that mentioned just now it can control the body temperature in hot situation and while exercising; thus it prevents one from having a heat stroke. It also prevents individual from toxins or chemicals by diluting them with sweat as they come in to contact with the skin. Some of the scientists found that sweating has smell that acts as scent. This scent sends secret signals to people around an individual. It is usually used for attracting your loved ones. Finally, sweat contains a natural antibiotic called dermicidin that helps to destroy bacteria on the skin.

But as everything has pros and cons, as well as sweating, over sweating is considered troublesome by many as it is clearly visible and obvious on the clothes and face. Besides, sweating caused bad odor, thus many people around you dislike it and they might move away from you. Sweating especially on hands makes it difficult to grab things and this might bring suffer also.







References:
Mosher HH (1933). "Simultaneous Study of Constituents of Urine and Perspiration". The Journal of Biological Chemistry 99: 781–790. http://www.jbc.org/cgi/reprint/99/3/781.pdf.

Chemistry of Cosmetics

The use of cosmetics is not a thing of the future. In fact, cosmetics were founded in Ancient Egyptian time. It was said that Ancient Egyptian women used kohl to darken their eyelids, and Cleopatra said to have bathed in milk to whiten and soften her skin. Not only that, Greek women used poisonous lead carbonate to achieve a pale looking complexion, and in the end claiming the life of the wearer due to its poisonous state. Today, cosmetics are big business. Cosmetic advertising are everywhere, attracting males and females who seriously cares about appearances.


What is a cosmetic? Cosmetic is defined as a substance or preparation intended for placemtn in contact with any external part of the human body. Cosmetics are used to cleanse, perfume, protect and change the appearance of the body or to alter its odours. Products that claim to modify bodily process or prevent diagnose, cure or alleviate any disease, ailment or defects are called therapeutics. This means that shampoos and deodorants are placed in the cosmetics category, while anti-dandruff shampoos and antiperspirants are considered therapeutics.

What do cosmetics contain? Most cosmetics contain water, emulsifier, preservative, thickener, colour, fragrance and pH stabilisers. For emulsifiers, emulsifiers are small droplets of oil dispersed in water or small droplets of water dispersed in oil.
Emulsifiers work by changing the surface tension between water and the oil, thus producing a homogeneous product with an even texture. As for preservatives, preservatives are added to prevent the growth of microoganisms, which can spoil the product and most probably harm the user. Preservatives used in cosmetics include parabens, benzyl alcohol and tetrasodium EDTA( ethylenediaminetetra-acetic acid).

Thickening agents such as polymers are often added to change the cosmetics consistency. Polymers can be synthetic (polyetylene glycol) or derived from natural sources (polysaccharides). Seaweed are common source of polysaccharides. Cosmetics that are too thick can be diluted with solvents such as water or alcohol.


Unfortunately, sometimes the ingredients in cosmetics can have unintended side-effects. For example, skin allergies to specific ingredients can be a problem. Allergies to cosmetic products can be due to chemicals such as added fragrances and preservatives. This can lead to skin rash where the product is applied. Chemicals causing the allergy can be avoided by reading product labels. Other people, which is not allergic to a specific ingredient, may nevertheless find the product irritates their skin becuase it damages the otuer layers, knwon as irritant dermatitis


Exfoliants and skin peels leave skin underneath temporarily more vulnerable to sun exprosure because they remove the outermost protective layer of dead skin cells. Excessive use of make-up or oily moisturiser can block pores and aggravate acne. More serious side effects are breast cancer with deodorants. Parabens, a class of chemicals commonly used as preservatives in deodorants and antiperspirants.

In the pursuit of beauty, there lies side effects. Therefore, it is wise to remember that cosmetics can be complex combinations of chemicals. Reading and understanding which ingredients are used in product are helpful when putting on cosmetics.




Referrence links,

http://www.science.org.au/nova/083/083key.htm

http://en.wikipedia.org/wiki/Cosmetics

http://www.badscience.net/category/cosmetics/

bad air breathed daily

Nowadays, seeing cars is as normal as seeing grasses and clouds. cars are the most basic transport for human especially city peoples. try to imagine if this world with no car exists, people will still be sitting horse cars, ox cars, rickshaws, dog sleds...and even pedal cars... i believe engine will be invented no matter what due to these inconveniences. well, what do modern cars really emits in our daily life? a point of fact, modern cars have two totally different personalities. one is friendly and attractive, the other one is destructive and lethal. how are cars so destructive? basically, gases produced by cars and emitted through car exhaust are poisonous and as mentioned, destructive. for instances, hydrocarbons, carbon monoxide, nitrogen oxide, particulates and sulphur dioxide.

Initially, hydrocarbons like unburned or half-burned fuel are a major contributor to urban smoke. It is toxic and will cause liver damage and even worst, cancer. Besides, hydrocarbons like methane, is also one of the greenhouse gases. It's environmental unfriendly and unhealthy for people as well. Secondly is the well-known gas which is carbon monoxide. Carbon monoxide is also a product of incomplete combustion. Inhaling carbon monoxide will cause the reduction to the ability of blood to carry oxygen. It will compete with oxygen to bind with a air transport mechanism in blood called haemoglobin. Overexposure may be fatal.

Besides that, when nitrogen in the air reacts with oxygen is a high temperature and pressure inside the engine, nitrogen oxides will be generated. It is a precursor to smog and acid rain. Nitrogen oxides will also destroy the resistance to respiratory infection. Especially delivery trucks, hot exhaust they blew containing life threatening amount of nitrogen oxides into the atmosphere. Particulate like soot or smoke that made up of particles in micrometre size range can cause respiratory health effects in both human and animals. Lastly, the sulphur oxides that emitted from motor vehicles burning fuel contain high concentration of sulphur.

Condition is getting worst due to the increasing of human population on earth. People keep purchasing cars without considering all these problems. However, it isn't too late to save ourselves. We could start carpooling from today onwards, take public transports, install catalytic converter on every single car and so on. I am afraid that we might have to wear poison gas mask around after 50 years later. Let's prevent this from happening!

The story between instant noodle and i

When you are hungry, what kind of food are you thinking about? Kentucky fried chicken, cheese cake…? Peoples usually would think about their favourite food when they are hungry. The first food that first come into my mind when I was hungry is instant noodles. Since I was young, I love to eat instant noodles. But I seldom consumed it because my mother always prevents me from cooking it. She says instant noodles are not good for our health. By the way, my desire to eating instant noodles becomes stronger and stronger because of the strictly controlled from my mother. So, every time when my mother when my mother is not at home, my sister and I would cook instant noodles secretly, without acknowledgement from our mother. There are very fun when we eat our favourite food, instant noodles, because we rarely have chance to consume it. Except that our mother is not at home. But we always discovered by our mother because we always remains some instant noodles in the basin of the kitchen. This was the funniest thing happen in my childhood. My favourite brand of instant noodles is cintan with the flavor of asam laksa . The taste of asam laksa of this brand are very special because it mixed with the taste of spicy and sour, and it really have fulfill my desire to taste two flavor at the same time.

Instant noodle was first invented in Japan. The price of instant noodles before are very expensive, but after the promoting, instant noodles become very commercial and its price become decreasing gradually. Nowadays, instant noodles are very cheaper staple food among Malaysian. It was very common food among Malaysian. But, instant noodles also got its disadvantages because of the low nutritional value. Instant noodles always get criticized among peoples as the unhealthy food. One packed of instant noodle contain high level of carbohydrate, fat, sodium and some may contain high level of protein. But it was low in vitamins, minerals, fibers and on the same times, it also contains high level of trans fat or saturated fat because of its manufacture process. Moreover, the flavoring powder in the instant noodles also contains high amount of MSG known as monosodium glutamate that may lead to headache, drowsiness, nausea if we consumes it too much.

Beside of this high level of carbohydrate, fat in instant noodles, the people that consume it in long period, would lead to malnutrition, obesity, high level of cholesterol, hypertension and so on. Actually instant noodle is a “no no” food for people who are on diet. One packet of instant noodles give you near to 2000KJ energy, about 65g of carbohydrate and almost 20g of fat. One packet of instant noodles may give you energy that is requiring by your body in whole day. The content of carbohydrate and also fat also excess the requirement for the normal adult in a day. So, if someone who are on diet consumed one packet of instant noodles in a day, would not help in the weigh lose because the amount of carbohydrate and fat are too high. But nowadays in order to fulfill the standard of health, the manufactures of instant noodle have successfully invent new type of instant noodles that are low in fat and without using monosodium glutamate as the flavoring. Besides, it also increases the content of fiber by using whole meal or wheat flour to make their noodles. The invention of new type of instant noodles has successfully get attention of many peoples especially who are on diet.

Eventhough, there are so many critics and side effect of instant noodles. But, I still love them. The most important thing is trying to reducing the times of consuming it. But love and enjoyed it when you having it. Enjoyed the moment when you having it, because after this time, you may have to wait a long time to consumed it again.

reference link: instant noodle(26 March 2010), http://en.wikipedia.org/wiki/instant_noodles, retrieved on 27 March 2010