Biology: Gene Structure and Function

Definition

A gene is a unit of heredity in a living organism. It is a segment of DNA that carries information from one generation to the next and is passed down from an organism's parents.

Structure

A gene consists of:

• Coding region: the part of the gene that codes for a protein
• Regulatory region: the part of the gene that controls when and how the gene is expressed
• Intron: a non-coding region within the gene
• Exon: a coding region within the gene

Function

Genes carry out their function by:

• Encoding proteins: genes provide the instructions for making proteins, which perform a wide range of functions in the cell
• Regulating gene expression: genes can turn on or off to control the amount of protein produced
• Influencing traits: genes determine the characteristics of an organism, such as eye color, hair color, and height

Types of Genes

• Protein-coding genes: genes that encode proteins
• Non-coding genes: genes that do not encode proteins, but instead regulate gene expression or perform other functions
• Pseudogenes: genes that are no longer functional due to mutations

Gene Expression

• Transcription: the process of creating a complementary RNA copy of the gene
• Translation: the process of using the RNA copy to build a protein
• Gene regulation: the process of controlling when and how genes are expressed, through mechanisms such as transcriptional regulation and post-transcriptional regulation