Bioinformatics Research Group at
Department of Computer Science
University of Nevada Reno
Definitions
Nucleic acid
Any of a group of complex compounds found in all living cells and viruses,
composed of purines, pyrimidines, carbohydrates, and phosphoric acid.
Nucleic acids in the form of DNA and RNA control cellular function and
heredity.
RNA
RNA stands for ribonucleic acid. It is a polymeric constituent of all living
cells and many viruses, consisting of a long, usually single-stranded chain
of alternating phosphate and ribose units with the bases adenine, guanine, cytosine,
and uracil bonded to the ribose. The structure and base sequence of RNA are
determinants of protein synthesis and the transmission of genetic information.
DNA
DNA stands for deoxyribonucleic acid, usually 2'-deoxy-5'-ribonucleic acid.
DNA is a code used within cells to form proteins. DNA is a nucleic acid that
carries the genetic information in the cell and is capable of self-replication
and synthesis of RNA. DNA consists of two long chains of nucleotides twisted
into a double helix and joined by hydrogen bonds between the complementary bases
adenine and thymine or cytosine and guanine. The sequence of nucleotides determines
individual hereditary characteristics.
Nucleotide
A nucleotide is any of various compounds consisting of a nucleoside combined
with a phosphate group and forming the basic constituent of DNA and RNA. A nucleotide
is a monomer (a small molecule) or the structural unit of nucleotide chains
forming nucleic acids as RNA and DNA. A nucleotide consists of a heterocyclic
nucleobase, a pentose sugar (ribose or deoxyribose), and a phosphate or polyphosphate
group. Nucleotides also play important roles in cellular energy transport and
transformations, and in enzyme regulation.
The nucleobase can be purines or pyrimidines, the sugar can be deoxyribose in
DNA or ribose in RNA, and the phosphate chain can be a monophosphate, diphosphate,
or triphosphate. A nucleotide that lacks the phosphate group is called nucleoside.
Gene Sequencing
Gene sequencing refers to the process of recording the exact sequence of nucleotides
in the section of an organism's DNA corresponding to a specific gene. Specific
genes of an individual with a certain phenotype (such as a disease) can be sequenced,
in an attempt to discover the phenotype's genetic basis. Gene sequencing can
also be referred as determination of the order in which the nucleotides are
strung together in a gene. Genome is all the genetic material in the chromosomes
of a particular organism.
