By Jessica Tran
Introduction
When water is transported from the roots to the mesophyll cells in the leaves, it is evaporates out the stomates, called transpiration, to create a lower osmotic potential. Osmotic potential is the part of the water potential of a tissue that results from the presence of solute particles. Even though the stomates open to release water, it also brings in carbon dioxide to produce sugar and oxygen through a process of photosynthesis. The water absorbed by the roots is moved by osmosis, root pressure, adhesion, and cohesion from high to low areas of water potential.
From the roots, water is transported with osmosis with a pressure pulling the water and minerals up towards the leaves. It is the transpirational pull moving it up with the help of cohesion and adhesion. Transpiration decreases the water potential causing water to move in and pull upward into the leaves and other areas of low water potential. Loss of water through transpiration can be facilitated by the opening and closing of the stomata depending on environmental condition. The rate of transpiration depends on several environmental factors such as light, humidity, temperature, and air movement, while the rate of evaporation depends on the water potential gradient, which is contributed by gravity, pressure, and solute concentration. The purpose of this experiment is to measure pressure changes on the different types of environmental factors that affect the rate of transpiration.
Hypothesis
If the temperature of an environment increases, then the rate of transpiration in plants will increase and will reduce the surface area of leaves.
Materials This lab requires a LabQuest, Vernier Gas Pressure Sensor, utility clamps, ring stand, a leaf with its stem, plastic tubing clamps, a pipette, a refrigerator, 300 milliliter beaker, plastic syringe, water, and graphing paper.
Procedures
First, connect the utility clamp on the ring