If you are fascinated by plants and how they grow, you might have wondered how they make their own food and use water. Plants are amazing organisms that can convert light energy into chemical energy and use water for various purposes. In this article, we will explore how transpiration and photosynthesis are related and why they are important for plants.
Contents
What is Transpiration?
Transpiration is the biological process by which water is lost in the form of water vapour from the aerial parts of the plants, such as leaves, stems, and flowers. Transpiration occurs mainly through the stomata, which are tiny pores on the surface of the leaves. The stomata allow carbon dioxide to enter and oxygen to exit during photosynthesis. They also regulate the loss of water vapour from the plant.
Transpiration is influenced by several factors, such as light, temperature, humidity, wind, and water availability. Generally, transpiration increases when the environmental conditions are dry, hot, bright, and windy. Transpiration decreases when the conditions are humid, cool, dark, and calm.
What is Photosynthesis?
Photosynthesis is the biochemical process by which plants use light energy to synthesize organic molecules, such as sugars, from carbon dioxide and water. Photosynthesis occurs in the chloroplasts, which are specialized organelles in the plant cells that contain chlorophyll, a green pigment that absorbs light.
Photosynthesis can be divided into two stages: light reactions and dark reactions. In the light reactions, water is split into oxygen and hydrogen ions using light energy. The oxygen is released as a by-product, while the hydrogen ions are used to generate ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate), which are energy carriers. In the dark reactions, also known as the Calvin cycle, carbon dioxide is fixed into organic molecules using ATP and NADPH.
How are Transpiration and Photosynthesis Related?
Transpiration and photosynthesis are related in several ways:
- Transpiration provides the water needed for photosynthesis. Water is one of the raw materials for photosynthesis, along with carbon dioxide. Without water, photosynthesis cannot occur.
- Transpiration creates a negative pressure gradient in the plant tissues that drives the upward movement of water and dissolved minerals from the roots to the leaves. This is known as the transpiration pull or the cohesion-tension theory. The water and minerals are essential for photosynthesis and other metabolic processes in the plant.
- Transpiration helps to cool down the plant by evaporating water from the leaf surface. This prevents overheating and damage to the photosynthetic machinery.
- Transpiration regulates the opening and closing of the stomata, which affects the gas exchange for photosynthesis. The stomata open when there is enough water in the plant cells and close when there is water deficit. This balances the need for carbon dioxide uptake and water loss prevention.
- Transpiration maintains the turgor pressure and shape of the plant cells. Turgor pressure is the internal pressure exerted by the water in the plant cells against the cell wall. It helps to keep the cells rigid and firm. Without turgor pressure, the cells would become flaccid and wilted.
Conclusion
Transpiration and photosynthesis are two vital processes for plants that are closely linked. Transpiration affects photosynthesis by providing water, minerals, cooling effect, gas exchange regulation, and turgor pressure. Photosynthesis affects transpiration by producing oxygen, sugars, ATP, and NADPH. Both processes are essential for plant growth and survival.
