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

Study of ancient dog DNA traces canine diversity to the Ice Age

A global study of ancient dog DNA, led by scientists at the Francis Crick Institute, University of Oxford, University of Vienna and archaeologists from more than 10 countries, presents evidence that there were different types ...

Denisovan DNA in the genome of early East Asians

Researchers have analyzed the genome of the oldest human fossil found in Mongolia to date and show that the 34,000-year-old woman inherited around 25 percent of her DNA from western Eurasians, demonstrating that people moved ...

New Denisovan DNA expands diversity, history of species

While the continents of Africa and Europe have been obvious and fruitful treasure troves for exploration and discovery of our modern human origins, Asia has been somewhat overlooked. Scientists have thought that modern humans ...

DNA sleuths target ivory poachers

Professor Adrian Linacre at Flinders University is part of a team that focuses on developing forensic DNA technology to thwart a thriving global black market in exotic animals—and the significance of this new test working ...

Researchers reveal why heat stress damages sperm

University of Oregon biologists have used the model organism Caenorhabditis elegans to identify molecular mechanisms that produce DNA damage in sperm and contribute to male infertility following exposure to heat.

Transcription factors may inadvertently lock in DNA mistakes

Transcription factor proteins are the light switches of the human genome. By binding to DNA, they help turn genes 'on' or 'off' and start the important process of copying DNA into an RNA template that acts as a blueprint ...

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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