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Smith, Michael (1932- ), British-born Canadian biochemist and Nobel Prize winner. Smith developed a method for altering the nucleic acid deoxyribonucleic acid (DNA) structure of protein molecules. His technique enabled scientists to determine with great accuracy t ....

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.... of crucial chemical functions in plants and animals. The best way to study the function of a specific protein is to mutate it, then observe how this changes the behavior of the entire organism. Prior to Smith's innovation, mutation was achieved by exposing random cells to mutagens (radiation or chemicals). This approach was unreliable because both radiation and chemicals mutated proteins randomly, making it impossible to determine how specific proteins had been affected. Scientists needed a way to deliberately alter a protein molecule's DNA structure (its sequence of amino acids). In the early 1980s Smith decided to try altering a viral DNA mol ....