Trp Operon Assignment

324 Words2 Pages
The gene regulation involving trp repressor protein differs from the one with the lac repressor according to many aspects. Firstly, lac repressor protein is active after being synthesized from the regulatory genes, it will bind to the operator site directly and the lac operon is turned “off” until lactose is present. However, the trp repressor protein is initially inactive and won’t hinder the trp operon unless tryptophan proteins are plentiful in the cells. Therefore, lac repressor protein starts working immediately after being produced, while trp repressor protein only works under the conditions of excess tryptophan molecules. To summarize, both operons make similar repressors that work to switch off the operon, but their repressions occur under different situations. The gene regulation involving lac repressor is controlled by the external product (lactose), but not the end product of the lac operon. On the other hand, the end product of the trp operon (tryptophan) will participate in the regulation of its own repression actively. If there was a mutation in the operator region so that operator could not carry out the function, then even after the trp repressor proteins was activated and bound with the excess tryptophan molecules, they would still lose ability to bind to the operator site. Accordingly, even though there were abundant repressor proteins, the trp operon would continue transcribing series of genes into RNA transcripts. The cell metabolism would be changed negatively as energies and raw materials were wasted, which will affect the other pivotal cell processes. If there was a mutation that altered the shape of trp repressor proteins, then the shape of allosteric sites might be changed as well, which means it would be challenging for tryptophan molecules (corepressor) to combine with them. As a result, the end product (tryptophan) of the trp operon
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