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How did studies of mutant microorganisms contribute to the one gene-one enzyme hypothesis?
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Metabolomics
In anabolic reactions, a cell uses energy to combine small molecules into larger molecules. In catabolic reactions, molecules are broken down, and energy is released.
The one geneāone enzyme hypothesis was advanced in the early 1940s by George Wells Beadle and Edward L. Tatum, who utilized the mold Neurospora crassa to demonstrate the link between genetics and biochemistry.12
Their research contributed to the hypothesis through the following experimental process:
- Inducing Mutations: The researchers exposed the mold to X-rays to create genetic mutations.12
- Identifying Metabolic Defects: They cultured the mutant strains in a minimal growth medium. While wild-type mold could survive on basic nutrients, the mutants often lost the ability to produce essential substances like specific amino acids or vitamins.12
- Linking Genes to Enzymes: By crossing these mutants with normal strains, they confirmed the defects were inherited as recessive genetic traits. They observed that when a specific gene was mutated, a corresponding chemical reaction in a metabolic pathway was disrupted because the enzyme catalyzing that reaction was either altered or missing.21
This work established that genes determine the structure of specific enzymes, effectively revealing the genetic control of metabolic processes.23