What is gene expression?

Gene expression is a fundamental biological process that involves the conversion of information encoded in a gene into a functional product, most commonly a protein. This process encompasses several stages, starting with the transcription of DNA into messenger RNA (mRNA), followed by the translation of that mRNA into a polypeptide chain, which then folds into an active protein.

This definition emphasizes the idea that gene expression is not just about producing RNA from DNA, but rather about utilizing that RNA to synthesize proteins that play critical roles in the cell's structure and function. Proteins are essential for carrying out various cellular activities, from catalyzing biochemical reactions as enzymes to providing structural support in cells.

By focusing on the creation of functional products, gene expression illustrates the link between genotype (the genetic information) and phenotype (the observable traits and characteristics) in an organism. Understanding gene expression is crucial for fields such as genetics, molecular biology, and biotechnology, as it lays the foundation for understanding how genes regulate complex biological processes.