Cells use a molecule called DNA as their design plans for proteins. DNA, or deoxyribonucleic acid, contains the genetic instructions needed for the development and functioning of living organisms. Within DNA, sequences of nucleotides encode the information for building proteins through a process known as gene expression.
When a cell needs to produce a specific protein, it first transcribes a segment of DNA into messenger RNA (mRNA). This mRNA then travels from the cell nucleus to the ribosomes, where it is translated into a protein by linking together amino acids in the order specified by the mRNA sequence. Thus, the information carried in DNA ultimately determines the structure and function of proteins, which perform a multitude of roles in the cell and the body.