Why does starch need to be insoluble?

Starch is an important carbohydrate that serves as the primary source of energy for plants. It is made up of glucose molecules and is stored in the form of granules in different parts of the plant, including the leaves, stems, and roots. Starch needs to be insoluble for several reasons, which are explained in detail below.

Prevents water loss
Starch is stored in the form of granules inside plant cells. If starch were soluble, it would dissolve in water and leak out of the cells, leading to loss of valuable energy resources. Insoluble starch prevents water loss by remaining within the cell walls and maintaining the osmotic balance of the cell.

Allows for storage
Starch is the main energy storage molecule in plants. It is stored in the form of granules in different parts of the plant, including the roots, leaves, and stems. Insoluble starch can be stored for long periods without being degraded, which allows plants to have a constant supply of energy.

Facilitates digestion
When plants need energy, the starch granules are broken down into glucose molecules. Insoluble starch is more resistant to digestion than soluble starch, which means that it takes longer to break down. This slows down the release of glucose into the bloodstream, providing a steady supply of energy over a longer period.

Enables transport
Insoluble starch is transported within the plant from the site of synthesis to the site of storage or use. If starch were soluble, it would be transported along with water and would not be able to reach its intended destination.

In conclusion, insoluble starch is essential for plants as it prevents water loss, enables energy storage, facilitates digestion, and allows for transport within the plant.