Conserved sequence: A conserved sequence is a DNA or protein sequence with a high degree of sequence identity to other sequences in that species, or in others.

Consensus sequence: A single sequence delineated from an alignment of multiple constituent sequences that represents a "best fit" for all those sequences. A "voting" or other selection procedure is used to determine which residue (nucleotide or amino acid) is placed at a given position in the event that not all of the constituent sequences have the identical residue at that position.

Central dogma: The path of information flow in DNA organisms (DNA -> RNA -> proteins).

Cyanobacterium: A photosynthetic bacterium of the class Coccogoneae or Hormogoneae, generally blue-green in color and in some species capable of nitrogen fixation. Cyanobacteria were once thought to be algae. Also called blue-green alga.

Clustal W: A widely used, general purpose algorithm for multiple sequence alignment of DNA or proteins

Codon: A sequence of three nucleotides in messenger RNA that codes for a single amino acid.

Cofactor: An inorganic molecule required by an enzyme in order to function.

Column: Database tables are composed of individual columns corresponding to the attributes of the object.

Complementary sequence: A sequence of bases that can form a double-stranded structure by matching base pairs.

Computational biology: A field incorporating computer science and biology.