Library · Genetics
Gene expression
Make it clearer
Gene expression is the path that leads from a gene to a protein. It takes two steps, each with its own name: transcription and translation.
Think of the gene as a recipe written in a library book, and of the library itself as the cell's nucleus. In transcription, an enzyme called RNA polymerase copies a piece of DNA into another molecule, RNA. That copy, messenger RNA, carries the message out of the nucleus to the cytoplasm, which is the rest of the cell's interior.
In translation, a structure called the ribosome reads that messenger RNA three nucleotides at a time; nucleotides are the letters it is written in. Each group of three is a codon and usually specifies an amino acid, one of the building blocks that make up a protein. Transfer RNA puts those building blocks in place one by one, and that is how the protein is built.
In brief
Gene expression is the path from a gene to a protein, and it involves two main steps: transcription and translation.
In transcription, RNA polymerase copies a segment of DNA into RNA; messenger RNA carries that message from the nucleus to the cytoplasm.
Messenger RNA is the copy of the recipe that leaves the nucleus.
In translation, the ribosome reads messenger RNA in codons, groups of three nucleotides that usually specify an amino acid, and transfer RNA builds the protein one amino acid at a time.
Sources (2)
- MedlinePlus, U.S. National Library of MedicineHow do genes direct the production of proteins?, MedlinePlus GeneticsPublished
- National Center for Biotechnology Information, StatPearls PublishingBiochemistry, Replication and Transcription, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated