DNA: see nucleic acid nucleic acid, any of a group of organic substances found in the chromosomes of living cells and viruses that play a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis.
..... Click the link for more information. .
One of two types of nucleic acid (the other is RNA); a complex organic compound found in all living cells and many viruses. It is the chemical substance of genes. Its structure, with two strands wound around each other in a double helix to resemble a twisted ladder, was first described (1953) by Francis Crick and James D. Watson. Each strand is a long chain (polymer) of repeating nucleotides: adenine (A), guanine (G), cytosine (C), and thymine (T). The two strands contain complementary information: A forms hydrogen bonds (see hydrogen bonding) only with T, C only with G. When DNA is copied in the cell, the strands separate and each serves as a template for assembling a new complementary strand; this is the key to stable heredity. DNA in cells is organized into dense protein-DNA complexes (see nucleoprotein) called chromosomes. In eukaryotes these are in the nucleus, and DNA also occurs in mitochondria and chloroplasts (if any). Prokaryotes have a single circular chromosome in the cytoplasm. Some prokaryotes and a few eukaryotes have DNA outside the chromosomes in plasmids. See also Rosalind Franklin; genetic engineering; mutation; Maurice Wilkins.
(2) (Digital Network Architecture) Introduced in 1978, it was Digital's umbrella term for its enterprise network architecture based on DECnet.
DNA
DNA
..... Click the link for more information. .
DNA
or deoxyribonucleic acid)
DNA double helix. A. Molecular model of DNA. The molecules include (1) hydrogen, (2) oxygen (3) …
(credit: © Merriam-Webster Inc.)
DNA
(1) See Windows DNA.(2) (Digital Network Architecture) Introduced in 1978, it was Digital's umbrella term for its enterprise network architecture based on DECnet.
DNA
deoxyribonucleic acid; a nucleic acid that is the main constituent of the chromosomes of all organisms (except some viruses). The DNA molecule consists of two polynucleotide chains in the form of a double helix, containing phosphate and the sugar deoxyribose and linked by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine. DNA is self-replicating, plays a central role in protein synthesis, and is responsible for the transmission of hereditary characteristics from parents to offspring
DNA
(biochemistry)
Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content.
| ?Page tools | ||
|---|---|---|
|