Plants have delicate structures essential for metabolism, reproduction, and growth. Many people may overlook the complexity of plants. Some plant structures are crucial to the process of photosynthesis. Stomata are one of those plant structures that are necessary for photosynthesis. What is stomata?
Stomata are plant cells that are on the outer surface of all plants that grow above ground. Stomata allow plants to absorb carbon dioxide and water and release oxygen and water vapor. This is because the stomata include a pore that is called a stoma. The other part of stomata is a guard cell. The inner walls of stomata guard cells are elastic and thick.
Plants have varying numbers of stomata. Grasses have fewer stomata than trees and some other plants. The number of stomata on a plant is referred to as the stomatal density. Stomatal density is expressed as the number of stomata per square millimeter. In such a tiny space as a square millimeter, there may be as many as one thousand stomata. The size and shape of stomata also vary among plants.
The stomata absorb carbon dioxide and water so that the plant can make simple sugars during photosynthesis. The simple sugars produced by photosynthesis provide energy for the plant. Without photosynthesis, plants could not live or grow.
Most photosynthesis occurs in the leaves of the plants. Little to no photosynthesis may occur in the stems of plants. During photosynthesis, water vapor and oxygen are released. The release of water vapor from the stomata is part of a process called transpiration.
The stomata of a plant open in response to potassium triggered by the reaction of light. Light and open stomata are necessary for photosynthesis. If a plant’s stomata remain open, the plant would lose too much water.
Stomata close in response to a hormone called abscisic acid. The hormone level triggers the closing of stomata when the water in the soil is lacking. By closing the stomata, the plant conserves water that would otherwise be lost through the stomata.
Stomata generally open in the morning and close at night. Plants in arid environments have stomata that open only at night since the plant would lose too much water vapor during the day. These plants store the carbon dioxide that they take in at night. Then, they can use this carbon dioxide during the day for photosynthesis since light is needed for this process.