One gene–one enzyme hypothesis

Definition

The one gene–one enzyme hypothesis states that each gene within an organism's genome codes for a single enzyme. This concept was fundamental in establishing the relationship between genes and metabolic pathways.

5 Must Know Facts For Your Next Test

1. The hypothesis was first proposed by George Beadle and Edward Tatum in the 1940s based on their work with Neurospora crassa.
2. It laid the groundwork for modern molecular biology by linking genes to specific biochemical functions.
3. This hypothesis has since been expanded to 'one gene–one polypeptide' because not all proteins are enzymes, and many proteins consist of multiple polypeptides encoded by different genes.
4. Mutations in a single gene can lead to defects in specific enzymes, which can result in metabolic disorders.
5. The experiment that led to this hypothesis involved inducing mutations in mold and observing the loss of function in specific metabolic pathways.

Review Questions

Related terms

Enzyme:

A protein that catalyzes biochemical reactions.

Gene Expression:

The process by which information from a gene is used to synthesize functional products like proteins.

Metabolic Pathway: A series of chemical reactions within a cell, facilitated by enzymes, that leads to a specific end product.