Medical research

Commonalities found between viral infections and ovarian cancer

DNA viruses, such as herpesviruses and poxviruses, are among the most prolific and deadly viruses on Earth. Their ability to proliferate widely is due in large part to the way these viruses incubate in the body. Many DNA ...

Diseases, Conditions, Syndromes

Platelets may play key role in development of lupus

Platelets may play a key role in the development of lupus, according to a study published today by researchers at Université Laval and CHU de Québec-Université Laval Research Center. Extracellular DNA circulating in the ...

Genetics

World's oldest DNA sequenced from million-year-old mammoths

Teeth from mammoths buried in the Siberian permafrost for more than a million years have yielded the world's oldest DNA ever sequenced, according to a study published on Wednesday, shining the genetic searchlight into the ...

Oncology & Cancer

Understanding the DNA repair toolkit to chart cancer evolution

The ongoing fight of science against cancer has made great strides, but cancer cells have not made it easy. The complexity of cancer cells and their adaptive evolutionary nature complicate the search for effective cures. ...

Oncology & Cancer

Liquid biopsy for colorectal cancer could guide therapy for tumors

A new study from Washington University School of Medicine in St. Louis demonstrates that a liquid biopsy examining blood or urine can help gauge the effectiveness of therapy for colorectal cancer that has just begun to spread ...

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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