beta-galactosidase
Quick Summary
Beta-galactosidase is an enzyme that breaks down galactosides. In organisms like Escherichia coli, its synthesis is controlled by a process called induction. This means the enzyme is only produced when its substrate, such as lactose or galactose, is present.12
This mechanism prevents the cell from wasting energy by making enzymes it doesn't need. Lactase, found in the human small intestine, is a similar enzyme that breaks down lactose into glucose and galactose. Mutations in the lactase gene can lead to lactose intolerance.3
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metabolismCoarse control…enzyme of this type is β-galactosidase. Escherichia coli growing in nutrient medium containing glucose do not utilize the milk sugar, lactose (glucose-4-β-d-galactoside); however, if the bacteria are placed in a growth medium containing lactose as the sole source of carbon, they synthesize β-galactosidase and can therefore utilize lactose. The reaction…
Read More…enzyme of this type is β-galactosidase. Escherichia coli growing in nutrient medium containing glucose do not utilize the milk sugar, lactose (glucose-4-β-d-galactoside); however, if the bacteria are placed in a growth medium containing lactose as the sole source of carbon, they synthesize β-galactosidase and can therefore utilize lactose. The reaction…
Read More- metabolismCoarse control
coli to form β-galactosidase when transferred to a medium containing lactose as the sole carbon source; such a transfer may result in an increase of 1,000-fold or more in the cellular concentration of the enzyme. Because this preferential enzyme synthesis is elicited by exposure of the cells to…
Read Morecoli to form β-galactosidase when transferred to a medium containing lactose as the sole carbon source; such a transfer may result in an increase of 1,000-fold or more in the cellular concentration of the enzyme. Because this preferential enzyme synthesis is elicited by exposure of the cells to…
Read More