The Utilization of Pentitols in Studies of the Evolution of Enzyme Pathways
Microbiologists generally agree that the earliest microorganisms to evolve were simple in their metabolic capabilities and had to be supplied with many preformed, complex molecules to satisfy their nutritional requirements. As time passed, certain organisms developed new metabolic pathways to synthesize such required compounds from smaller, less complex molecules and thus became more versatile in their nutritional requirements, utilizing a wider range of food sources. Changes in the metabolism of higher organisms must have produced new types of organic compounds that entered the environment upon the death of the organisms. Micro-organisms, in turn, evolved metabolic pathways for the degradation of these new molecules and used them to obtain carbon and energy to satisfy their growth requirements. The extra DNA provided by the duplication of previously existing genes may have been modified through mutation to eventually become the structural and regulatory genes for new degradative pathways.
KeywordsCatabolic Pathway Enzyme Pathway Chemostat Experiment Aerobacter Aerogenes Constitutive Synthesis
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