However, when the mutant cells deplete the glucose in their medium, they quickly die, in contrast to wild-type cells that stop growing but remain viable. Suggest a biochemical explanation for the difference in the behavior of wild-type and mutant cells. When fixed nitrogen is supplied, both cell types can survive running out of glucose, so there is nothing wrong with their ability to stop growing and enter a resting state. However, only when required to fix N 2 does the mutant suffer. Therefore, the inability to survive glucose deprivation probably has something to do with its nitrogenase system.
Some plants are able to well grow in saline soil that contains a high concentration of salt.
This process, of course, is costly to the cells, and requires the expenditure of extra ATP to keep the cells happy in saline soil. An experimental drug was being developed that it was hoped would inhibit the enzyme ferrochelatase and would be useful in the treatment of a rare disease in which patients accumulate toxic levels of heme because they can't degrade or excrete it. One candidate drug was found to decrease the rate of heme synthesis when administered to patients. However, a major side effect was that the patients accumulated protoporphyrin in their skin and became photosensitive. In carefully controlled in vitro experiments, it was determined that, contrary to expectations, the drug does not inhibit ferrochelatase.