why do plants need water for photosynthesis

Plants use a complex chemical reaction called photosynthesis to create food from light energy, carbon dioxide from the atmosphere, and water. Each of these performs a critical portion of the photosynthesis process, dependent on the others. While light energy can be easily absorbed from the sun and carbon dioxide from the atmosphere, water is sometimes scarce. Not only is water used directly in the process of photosynthesis for its hydrogen, it is also used to prevent dehydration, indirectly supporting the successful creation of food for the plant. The leaves of plants contain openings called stomata, which are used for the exchange of gases. Carbon dioxide, combined with water in photosynthesis, is drawn in through the stomata. Oxygen, a byproduct of the process, is released through these openings, along with water vapor in a process called transpiration. During dry seasons, however, the plant must conserve moisture as much as possible. In order to do this, the plant closes the stomata, preventing the escaping of water vapor.


The stomata can only be closed through use of guard cells, which are filled with water to close the stomata, and seal moisture within the plant. In addition to the indirect support that water offers the photosynthesis process, it is also necessary for the chemical reaction that takes place. During this process, the light energy reacts with a pigment called chlorophyll, and excites the electrons. The resultant charge converts the light energy into chemicals called adenosine triphosphate, also known as ATP, and nicotinamide adenine dinucleotide phosphate, or NADPH. These chemical compounds are used to store the energy absorbed from the sun. During the energy storage process, water molecules, which are made up of hydrogen and oxygen, are split so that these elements are separate. The hydrogen is then combined with carbon dioxide with the help of ATP and NADPH, to become sugar, which is used as energy for the plant. The process of turning carbon dioxide in the atmosphere into a usable form of energy is called carbon fixation.
Why Do Plants Need Water?


Why do plants need water? The easy answer is, because they re made mostly of water. But let s take it a little further Why Do Plants Need Water? Reason 1: Germination Germination is the process of a newborn plant emerging from its seed. A seed needs water to activate the enzymes that orchestrate the germination process. Absorbed water also causes the seed to swell and soften which makes it possible for the plant to break through. Why Do Plants Need Water? Reason 2: Photosynthesis The enzymes contained within each seed give it enough juice to push the sprouting plant to the surface. After it gets there, light energy, carbon dioxide and water take over. Very generally put, photosynthesis (literally putting together or synthesizing light) produces food for the plant by combining light energy, carbon dioxide and water, each of which (along with nutrients from the soil) is needed in order for the plant to grow.


Why Does a Plant Need Water? Reason 3: Nutrient transfer Water is a necessary conduit for the transfer of nutrients from the soil and into the root system. Without it, the soil s nutrients could not be absorbed by the plant. Why Does a Plant Need Water? Reason 4: Transpiration Often confused with and not completely dissimilar from evaporation, transpiration is the process of water being pulled in through the roots, up the stem and out of the plant. It serves three main purposes: Causes nutrients and water to flow throughout the plant, thereby feeding and hydrating it Transpiration becomes evaporation the instant it leaves the surface of the plant and heads into the atmosphere. Was this page helpful? If so, please tell your friends about it with a Facebook like or via Twitter, Pinterest, email or good old fashioned word of mouth. Thank you for supporting our efforts! Also see. Sources: Definitions obtained from

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