In the absence of lactose, the repressor protein encoded by the I gene binds to the lac operator and prevents transcription. Binding of allolactose to the repressor causes it to leave the operator. This enables RNA polymerase to transcribe the three genes of the operon.
A tough-skinned tropical fruit, the mango features a sweet, orange- to red-color flesh inside when ripe. Kensington pride, Kent, Palmer and sensation are only a few of the many varieties of mango available through groceries and markets.
According to About.com, a mango is ripe enough to eat if it gives a little bit when squeezed and if it has a fragrant aroma. A mango's color does not indicate ripeness. Continue Reading. Whole, ripe mangoes keep for up to five days if refrigerated. Unripe mangoes ripen if left at room temperature. Placing them in a paper bag speeds the ripening process. Peeled, diced mango can be placed in an airtight container and stored in the refrigerator for a few days. It can also be coated with sugar and frozen for up to six months.