Answer: The final product of gene expression is a functional molecule, most commonly a protein; for many genes, the final product is a protein, while for others it is a functional RNA molecule. Overview
- Gene expression encompasses the process by which the information encoded in a gene is used to produce a functional product. For protein-coding genes, this product is typically a protein. For non-coding genes, the final product is an RNA molecule that has a functional role in the cell. This distinction reflects the two major outcomes of transcription and subsequent processing/translation in cells.
Details
- Protein-coding genes: DNA is transcribed into messenger RNA (mRNA), which is then translated by the ribosome to form a polypeptide chain that folds into a functional protein. Thus, the final product is a protein.
- Non-coding genes: Some genes are transcribed into RNA that does not code for a protein but functions as RNA (e.g., rRNA, tRNA, miRNA, siRNA, lncRNA). In these cases, the final gene product is the RNA molecule itself, performing structural, catalytic, or regulatory roles.
Common phrasing in textbooks
- Many sources summarize that gene expression results in either a protein or a functional RNA molecule, depending on the gene type. This framing is consistent across educational materials and reference databases.
If you’d like, I can tailor this to a specific organism or gene type (protein- coding vs non-coding) and cite sources more precisely.