How do plants store carbohydrates produced in photosynthesis?

Plants store the carbohydrates produced in photosynthesis mainly as starch in their leaves, stems, roots, and fruits.

Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy, usually from the sun, into chemical energy in the form of glucose. This glucose is then used by the plant for growth and reproduction. However, not all the glucose produced is used immediately. The excess glucose is converted into starch and stored in various parts of the plant for later use.

Starch is a polysaccharide, a large molecule made up of many glucose units linked together. It is an ideal storage form of glucose because it is insoluble in water and does not affect the osmotic balance of the cells. This means it does not draw water into the cells by osmosis, which could cause them to swell and burst.

The process of converting glucose into starch takes place in the chloroplasts, the same organelles where photosynthesis occurs. The glucose molecules are joined together by a process called dehydration synthesis, which involves the removal of a water molecule. This process is facilitated by enzymes, which are proteins that speed up chemical reactions.

The starch is stored in the form of granules within the chloroplasts or in specialised storage cells. In leaves, the starch is used during the night when photosynthesis cannot occur. In stems, roots, and fruits, the starch can be converted back into glucose and used when the plant needs additional energy, for example during periods of rapid growth or when the plant is not photosynthesising, such as in winter.

In summary, plants have a very efficient system for storing the excess carbohydrates produced during photosynthesis. They convert the glucose into starch, an insoluble molecule that does not disrupt the osmotic balance of the cells, and store it in various parts of the plant for later use.