News tagged with dna

Related topics: genes , protein , cells , genome , chromosomes

Vitamins can damage the body's own defences

Each year, we spend billion of dollars on dietary supplements. New research indicates that vitamin pills may upset the fragile balance in our cells and thus cause more harm than good.

Nov 26, 2013
popularity 3.8 / 5 (21) | comments 4

Key to aging immune system is discovered

There's a good reason people over 60 are not donor candidates for bone marrow transplantation. The immune system ages and weakens with time, making the elderly prone to life-threatening infection and other ...

Jul 31, 2014
popularity 4.8 / 5 (13) | comments 0

One in four has alarmingly few intestinal bacteria

All people have trillions of bacteria living in their intestines. If you place them on a scale, they weigh around 1.5 kg. Previously, a major part of these 'blind passengers' were unknown, as they are difficult or impossible ...

Aug 28, 2013
popularity 5 / 5 (12) | comments 1 | with audio podcast

Interactive map of human genetic history revealed

The interactive map, produced by researchers from Oxford University and UCL (University College London), details the histories of genetic mixing between each of the 95 populations across Europe, Africa, Asia ...

Feb 13, 2014
popularity 5 / 5 (10) | comments 2 | with audio podcast

3-D model links facial features and DNA

DNA can already tell us the sex and ancestry of unknown individuals, but now an international team of researchers is beginning to connect genetics with facial features, degrees of femininity and racial admixture.

Mar 20, 2014
popularity 4.9 / 5 (10) | comments 0

Biologists ID new cancer weakness

About half of all cancer patients have a mutation in a gene called p53, which allows tumors to survive and continue growing even after chemotherapy severely damages their DNA.

Nov 14, 2013
popularity 4.6 / 5 (9) | comments 0 | with audio podcast

DNA

Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints or a recipe, or a code, since it contains the instructions needed to construct other components of cells, such as proteins and RNA molecules. The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information.

Chemically, DNA consists of two long polymers of simple units called nucleotides, with backbones made of sugars and phosphate groups joined by ester bonds. These two strands run in opposite directions to each other and are therefore anti-parallel. Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information. This information is read using the genetic code, which specifies the sequence of the amino acids within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA, in a process called transcription.

Within cells, DNA is organized into X-shaped structures called chromosomes. These chromosomes are duplicated before cells divide, in a process called DNA replication. Eukaryotic organisms (animals, plants, fungi, and protists) store most of their DNA inside the cell nucleus and some of their DNA in the mitochondria (animals and plants) and chloroplasts (plants only). Prokaryotes (bacteria and archaea) however, store their DNA in the cell's cytoplasm. Within the chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.

This text uses material from Wikipedia licensed under CC BY-SA