The form from a piece of membrane breaking loose from a cell and storing substances is called a vesicle.

Here's a breakdown:

* Vesicles are small, membrane-bound sacs that transport substances within cells or between cells.

* How they form: They can form from the pinching off of a portion of the cell membrane or from the Golgi apparatus.

* Storing substances: Vesicles can store various substances, including:

* Waste products: For removal from the cell.

* Enzymes: For specific reactions within the cell.

* Hormones: For communication between cells.

* Nutrients: For transport within the cell.

Let me know if you have any other questions!