# Leaf Transpiration Lab

## Problem:

"Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere ... Transpiration also includes a process called guttation, which is the loss of water in liquid form from the uninjured leaf or stem of the plant, principally through water stomata," (U.S. Geological Survey, 2011 (b)).

Will adding crystal light to water affect the rate of transpiration? If so, how was the transpiration rate affected, negatively or positively?

## Hypothesis:

If we add a packet of crystal light powder to plain water, then the solution created when the two are mixed together will decrease the transpiration rate of the leaf over the course of 15 minutes because the sugars will cause the water potential to decrease creating less pressure.

## Description of the Experiment

Manipulated Variable

• 1 Packet of crystal light added to the of water

Range to be Used

• 10 minutes 30 seconds, data will be acquired every minute and a half.

Three Constant Factors

• Amount of light, light will be provided by overhead lights in the classroom
• Temperature- the temperature will stay a constant 20 degrees celsius
• Type of leaf

Manipulated Variable Procedure

• Gather all supplies needed
• Pour water in plastic bin
• Add an entire packet of crystal light to the water
• Mix until the water turns red
• Trace the leaf on a piece of graph paper in order to be able to calculate the area of the leaf
• Set up titration setup
• Completely submerge the tube and pipette in the water
• Using the syringe, add the crystal light and water solution to the tube
• After the setup is complete, attach the leaf
• Using the petroleum jelly, create an air-tight seal
• Start a timer
• Record data every minute and thirty seconds

## Control Procedure

• Gather all supplies needed
• Pour water in plastic bin
• Trace the leaf on a piece of graph paper in order to be able to calculate the area of the leaf
• Set up titration setup
• Completely submerge the tube and pipette in the water
• Using the syringe, add water to the tube
• After the setup is complete, attach the leaf
• Using the petroleum jelly, create an air-tight seal
• Start a timer
• Record data every minute and thirty seconds

Their is no manipulated variable in this setup.

## Analysis

We put the stem leaf into the tube filled with crystal light (which was added to water). For fifteen minutes, time was kept every minute and a half. Then was charted on a spread sheet.

## Conclusion

We found that the crystal light powder added to the water did affect the transpiration of the leaf. It had small changes throughout the time.