Definition: DNA (deoxyribonucleic acid) is a type of macromolecule known as a nucleic acid. It is shaped like a twisted double helix and is composed of long strands of alternating sugars and phosphate groups, along with nitrogenous bases (adenine, thymine, guanine and cytosine). DNA is organized into structures called chromosomes and housed within the nucleus of our cells. DNA is also found in cell mitochondria. DNA contains the genetic information necessary for the production of cell components, organelles, and for the reproduction of life. Protein production is a vital cell process that is dependent upon DNA. Information contained within the genetic code is passed from DNA to RNA to the resulting proteins during protein synthesis. DNA is composed of a sugar-phosphate backbone and nitrogenous bases. In double-stranded DNA, the nitrogenous bases pair up. Adenine pairs with thymine (A-T) and guanine pairs with cytosine (G-C). The shape of DNA resembles that of a spiral staircase. In this double helical shape, the sides of the staircase are formed by strands of deoxyribose sugar and phosphate molecules. The stair steps are formed by the nitrogenous bases. The twisted double helix shape of DNA helps to make this biological molecule more compact. DNA is … Continue reading →

Genes are the blueprints of life. Genes control everything from hair color to blood sugar by telling cells which proteins to make, how much, when, and where. Genes exist in most cells. Inside a cell is a long strand of the chemical DNA (deoxyribonucleic acid). A DNA sequence is a specific lineup of chemical base pairs along its strand. The part of DNA that determines what protein to produce and when, is called a gene. First established in 1985 by Sir Alec Jeffreys, DNA testing has become an increasingly popular method of identification and research. The applications of DNA testing, or DNA fingerprinting within forensic science is often what most people think of when they hear the phrase. Popularized by television and cinema, using DNA to match blood, hair or saliva to criminals is one purpose of testing DNA. It is also frequently used for other benefits, like wildlife studies, paternity testing, body identification, and in studies pertaining to human dispersion.While most aspects of DNA are identical in samples from all human beings, concentrating on identifying patterns called microsatellites reveals qualities specific and unique to the individual. During the early stages of this science, a DNA test was performed using … Continue reading →

A DNA-based sunscreen that not only stops harmful ultraviolet (UV) light, but also becomes more protective the longer you expose it to UV rays? Thats the dazzling premise behind a recent study published in the journal Science Reports. While sunscreen isnt the only form of sun protection (theres always protective clothing and floppy hats), the reality is that most of us just skip it. A 2015 study in Journal of the American Academy of Dermatology found that only 14.3 percent of men and 29.9 percent of women routinely use sunscreen when they are in outside for more than an hour. This wouldnt be a problem, except, Ultraviolet light is a carcinogen, Guy German a biomedical researcher at Binghamton University in New York and an author on the study, tells PopSci. We know it can give you a tan, but it can also cause cancer as well. While dermatoepidemiologists (scientists who study diseases of the skin) suspect that sunlight causes cancer because it damages DNA in our cells, German and his colleagues were looking at DNA in an entirely different way. They wondered what would happen if they exposed DNA film, essentially a thin sheet of the stuff, to the same … Continue reading →

Five years ago, Alice Collins Plebuch made a decision that would alter her future or really, her past. She sent away for a "just-for-fun DNA test." When the tube arrived, she spit and spit until she filled it up to the line, and then sent it off in the mail. She wanted to know what she was made of. Plebuch, now 69, already had a rough idea of what she would find. Her parents, both deceased, were Irish-American Catholics who raised her and her six siblings with church Sundays and ethnic pride. But Plebuch, who had a long-standing interest in science and DNA, wanted to know more about her dad's side of the family. The son of Irish immigrants, Jim Collins had been raised in an orphanage from a young age, and his extended family tree was murky. After a few weeks during which her saliva was analyzed, she got an email in the summer of 2012 with a link to her results. The report was confounding. About half of Plebuch's DNA results presented the mixed British Isles bloodline she expected. The other half picked up an unexpected combination of European Jewish, Middle Eastern and Eastern European. Surely someone in … Continue reading →