News tagged with dna

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

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 (16) | comments 1

New paper describes how DNA avoids damage from UV light

In the same week that the U.S. surgeon general issued a 101-page report about the dangers of skin cancer, researchers at Montana State University published a paper breaking new ground on how DNA – the genetic code in every ...

Jul 31, 2014
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Study shows epigenetic changes can drive cancer

Cancer has long been thought to be primarily a genetic disease, but in recent decades scientists have come to believe that epigenetic changes – which don't change the DNA sequence but how it is 'read' – also play a role ...

Jul 26, 2014
popularity 4.9 / 5 (7) | comments 2

Study finds crucial step in DNA repair

Scientists at Washington State University have identified a crucial step in DNA repair that could lead to targeted gene therapy for hereditary diseases such as "children of the moon" and a common form of ...

Aug 18, 2014
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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