This investigation addressed the question of whether a change in environmental conditions, specifically the addition of fertilizer to a plant s water source, affects the rate of transpiration. Transpiration is the loss of water via evaporation through pores on the stems and leaves of plants. Transpiration plays an integral role in the flow of water through a plant as water loss through stomata results in water molecules being pulled into the plants through the roots. That is, as water is lost from leaves due to evaporation, water molecules from adjacent cells flow into the leaf via osmosis. Water molecules have the property of hydrogen bonding, which helps water molecules to stick together.
Water molecules travel up the xylem to the leaves due to the pressure difference within the xylem.
As a result, water molecules enter the root cells, which have become water deficient as a result of the flow of water to the leaves, thereby perpetuating the flow of water through a plant. The hydrogen bond is a weak interaction between a hydrogen atom bonded to an oxygen, nitrogen, or fluorine atom in another molecule. Because the hydrogen bond is a weak association, it is more easily broken than a covalent bond. The ramifications of breaking a hydrogen bond within the water column of a plant are great as the steady flow of water is dependent upon a tension created by an unbroken chain of water molecules. By breaking one or more hydrogen bonds, the plant is unable to transpire at its optimal rate.