HMB265H1 Chapter Notes -Auxotrophy, Pheromone, Archibald Garrod
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HMB265H1 Full Course Notes
Verified Note
25 documents
Document Summary
Genes act by controlling cellular chemistry several human diseases have defects in metabolism (the general set of chemical reactions taking place in an organism) Archibald garrod made this discovery, came up with the notion that such genetic diseases are. Observations of alkaptonuria (aku) led to the possibility that the cell"s chemical pathways were under control of a large set of interacting genes. George beadle and edward tatum used neurospora fungus to demonstrate this control. Irradiated neurospora cells to produce mutations, then tested cultures grown from ascospores for unusual mutant phenotypes relevant to biochemical function. Each mutation that generated a nutrient requirement was inherited as a single-gene mutation b/c each gave a 1:1 ratio when crossed with a wild type: + x aux progeny: + and aux. One-gene-one-enzyme hypothesis source of the first exciting insight into the functions of genes; genes were somehow responsible for enzyme function, and each gene controlled one specific enzyme in a series of interconnected steps.
