Genes are portions of deoxyribonucleic acid (DNA), which can act to control cell structure and functions, as well as the functioning of other genes. The set of genes in a living organism is called the genome, or genetic material. The location of a gene within the chromosome that houses it is called a locus.
Chemically, each gene is made up of a sequence of nucleotides, which in turn consist of a nitrogenous base, a sugar and a phosphate group.
Gene expression involves the formation of a ribonucleic acid (RNA) from the portion of DNA corresponding to that gene, through a process called transcription.
This RNA, formed from the expression of a gene, will be responsible for the production of a specific protein, through a process known as translation.
In turn, this specific protein can perform several functions, including the following:
Composition of one of the various structures of the cell;
Participation in chemical reactions responsible for the functioning of the cell;
Regulating the functioning of the cell itself and/or other cells;
Regulatory action of gene expression.
In summary, genes control all cellular processes and characteristics. For this reason, changes in the structure of genes, known as mutations, can lead to the formation of defective proteins, with possible consequences for the structure and normal functioning of cells.