A nucleic acid that constitutes the genetic material of all cellular organisms and the DNA viruses.
A polymer of subunits called deoxyribonucleotides which is the primary genetic material of a cell, the material equivalent to genetic information.
Chemical substance found in chromosomes within cell nuclei; its molecular structure contains the organism’s genetic information.
The genetic material in the nuclei of all cells. A linear polymer composed of four kinds of deoxyribose nucleotide, adenine, cytosine, guanine and thymidine (A, C, G and T), linked by phosphodiester bonds, that is the carrier of genetic information. In its native state DNA is a double helix.
Discovered by Frederick Miescher in 1869, it is the chemical basis for genes. The chemical building blocks (molecules) of which genes (i.e., paired nucleotide units that code for a protein to be produced by a cell’s machinery, such as its ribosomes) are constructed. Every inherited characteristic has its origin somewhere in the code of the organism’s complement of DNA. The code is made up of subunits, called nucleic acids. The sequence of the four nucleic acids is interpreted by certain molecular machines (systems) to produce the required proteins of which the organism is composed. The structure of the DNA molecule was elucidated in 1953 by James Watson, Francis Crick, and Maurice Wilkins. The DNA molecule is a linear polymer made up of deoxyribonucleotide repeating units (composed of the sugar 2- deoxyribose, phosphate, and a purine or pyrimidine base). The bases are linked by a phosphate group, joining the 3′ position of one sugar to the 5′ position of the next sugar. Most molecules are double-stranded and antiparallel, resulting in a right-handed helix structure that is held together by hydrogen bonds between a purine on one chain and pyrimidine on the other chain. DNA is the carrier of genetic information, which is encoded in the sequence of bases; it is present in chromosomes and chromosomal material of cell organelles such as mitochondria and chloroplasts, and also present in some viruses.
DNA is the genetic material from which chromosomes are formed. DNA is involved in protein synthesis and in inheritance. Because of DNA’s structure (a double helix), exact replication occurs during cell division.
This class of nucleic acids, which are found chiefly in the nucleus of cells, causes transference of genetic characteristics and synthesis of proteins.
Genetic material composed of the genes that, in turn, make up the chromosomes is self-duplicating. There are four kinds of nitrogenous bases in a single molecule adenine, cytosine, guanine, and thymine.
The genetic material in the nucleus and mitochondria. DNA dictates all the genetically determined characteristics. Each of these characteristics is coded by the sequence of purine and pyrimidine bases that are connected together in a double-stranded helix.
The process whereby proteins are synthesized provides the basis for understanding genetic differences. It is also the basis for understanding how the unique properties of each cell type are maintained, since the properties that make cells unique are usually conferred by the proteins within them. Some of these proteins are the structural elements of the cell. Others are enzymes that catalyze specific reactions and processes that characterize the cell in question. Still other proteins confer a particular biochemical function on the cell. The amino acid sequence of a particular protein is genetically controlled. This control is exerted through the polynucleotide, DNA. DNA is found in both the nucleus and the mitochondria. It is composed of four bases: adenine, guanine, thymine, and cytosine. These bases are condensed to form the DNA chain in a process analogous to the condensation of amino acids that comprise the primary structure of a protein. Species vary in the percent distribution of these bases in their DNA. In mammals, the adenine-thymine content varies from 45% to 53%. Small amounts of the base, 5-methyl cytosine, as well as methylated derivatives of the other bases, can also be found.
Large molecule shaped like a double helix and found primarily in the chromosomes of the cell nucleus; it contains the genetic information of the cell. The genetic information is coded in the sequence of subunits (nucleotides) making up the DNA molecule. Nucleotides contain one of four bases (adenine, guanine, cytosine, or thymine), a sugar (deoxyribose), and a phosphate (phosphorus-containing) group; they are held together by hydrogen bonds.
A nucleic acid that is an essential component of a chromosome; that carries the genetic information of the organism.
Commonly known as DNA, the fundamental genetic component of all cellular organisms and some viruses. DNA is the material that forms the structure of genes. With the exception of identical twins, each person’s DNA is unique. In any one individual, DNA is a component of each cell and is identical in every cell, whether a skin cell, bone cell, or other cell. DNA gives cells their specialized functions.
The molecule that carries the genetic information for most living systems. The DNA molecule which carries genetic information consists of four bases (adenine (A), thymine (T), guanine (G), and cytosine (C)) and a sugar-phosphate backbone, arranged in two connected strands to form a double helix. Each of the two connected strands is called a single strand.
A complex nucleic acid of high molecular weight consisting of nucleotides made of deoxyribose, phosphoric acid, and one of four bases (two purines, adenine and guanine, and two pyrimidines, thymine and cytosine). These nucleotides are arranged as two long chains that twist around each other to form a double helix joined by hydrogen bonds between the complementary base pairs A-T and C-G. Nucleic acid, present in chromosomes of the nuclei of cells, is the chemical basis of heredity and the carrier of genetic information for all organisms except the RNA viruses. Formerly spelled desoxyribonucleic acid.