Genes: the code of life
What is - definition
The gene is the fundamental unit of heredity. Each gene is made up of a specific sequence of nucleic acids (the most important cell control biomolecules because they contain genetic information. There are two types of nucleic acids: deoxyribonucleic acid - DNA - and ribonucleic acid - RNA).
Summary of Key Functions, Location, and Other Information
Genes control not only the structure and metabolic functions of cells, but also the entire organism. When located in reproductive cells, they pass their information on to the next generation.
Chemically, each gene consists of a DNA sequence that forms nucleotides (energy-rich compounds that assist metabolic processes, especially biosynthesis in most cells).
Nucleotides are composed of a nitrogenous base, a pentose (sugar with five carbon atoms) and a phosphate group. Nitrogenous bases can be classified into: pyrimidines and purines.
The gene is usually located interspersed with non-protein encoded DNA sequences. These sequences are referred to as "useless DNA". When this type of DNA occurs within a gene, the coded portion is classified as uncoded part.
Useless DNA makes up 97% of the human genome and, despite its name, it is necessary for the proper functioning of genes.
In each species there is a definite number of chromosomes. Changes in their number or disposition of genes can result in genetic mutations.
When germ cell mutations (egg or sperm) occur, the changes can be passed on to future generations. Mutations that affect somatic cells can result in certain cancers.
The genetic constitution of an organism (genotype) plus the influence received from the environment will be responsible for the phenotype, ie, the observable characteristics of the individual.
The sum total of the genes is called the genome. Research conducted as the goal of identifying the location and function of each gene is known as the human genome.