The respiration in plants is continuous day and night. The oxygen from the air spaces in the leaves and stems diffuses into tissues and cells of the plants after getting dissolved in the film of water present over the cells. In the cells this oxygen oxidizes the carbohydrates and other organic compounds into carbon dioxide and water to produce energy. Some ratio of carbon dioxide is used in the process of photosynthesis. The rest of carbon dioxide and some of the water (vapors) collect in the air spaces from where they pass out to the exterior through lenticels and stomata. The water produced in this process also becomes a part of already present water in the body of plants. The process of oxidation or respiration in plants consists of many enzymatic reactions. This process occurs at a faster rate in the parts of the plants having rapid growth like growing seeds, buds, apical meristem of roots and shoots, because these parts require more energy to accomplish the growth process. The gaseous exchange in plant is not very evident during the day time as the products of respiration i.e. Carbon dioxide and water are the reactants in the process of photosynthesis. So, the carbon dioxide and water produced in the respiration are utilized in photosynthesis, occurring in the day light.
