The Opening and Closing of the Stomata In Plants

The stomata is a structure in a plant cell that allows water or gases to be let into the plant. The stomata is made up of two components , the guards cell and the stoma, which have varying functions. The guard cells in the stomata open or close, causing the stoma to open or close, depending on the environment. The stoma is the actually opening which allows water to escape the plant and gases, especially carbon dioxide, to come in. The guard cells tend to open when the cell becomes turgid, or filled with to much water. By opening up, the guard cells allow the stoma to open and release the water. The stoma must also be open during photosynthesis to bring in carbon dioxide and allow oxygen to leave. Different factors can cause the stomata to open or close.

Normally the stomata is closed at night and open during the day because of photosynthesis. The plant cannot perform photosynthesis at night, because there is no sunlight, so the stomata closes to prevent loss of water and gases. It then opens up again during the day so that the plant can release oxygen during photosynthesis and regain CO2. However some environmental factors could cause the stomata to act abnormally. For example if there were many rainstorms, causing flooding, the plant cell may become turgid from absorbing to much water. The guard cells would open allowing the stoma to release the excess water to escape even at night. Another environmental factor that could cause the stomata to behave abnormally is a drought. When the plant can't receive enough water the stomata has to close to prevent the plant from becoming flaccid. The stomata may close, or mostly close, during the day to keep as much water in the cell as possible to stop the plant from wilting. This would stop the process of photosynthesis which would stop the plant from making it's food and surviving. The plant would have to rely on it's sugar sink until water was more readily available , or the plant died.

The stomata play a very important role in the function of a plant. The plant would not be able to gauge how much water needs to be lost or kept inside without the guard cells of a stomata. Without the stoma no photosynthesis or transpiration could occur because there would be no opening to release water and oxygen nor to gain CO2.