The Role of CO2 in PhotosynthesisGroup 1 - Lorenzo Daniel L. Antonio, Paolo Carlo Calalang, Timothy Carandang, Oneil Joshua Calderon, MHAB1

Submitted to: Ma’am Elena M. Ragragio

Submitted: September 20, 2012

Introduction

In the process of photosynthesis of a plant, plants need raw materials such as light and CO2 are needed to complete this process. Light contains the energy needed by the plant in the process, and CO2 contains carbon needed to create sugar compounds

Objectives

The objective is to determine if CO2 is important and essential to the plant in the process of photosynthesis.

Hypothesis

Plants need to absorb CO2 in because it needs the carbon in the compound. After splitting it up, it will take carbon to create sugars and release oxygen.

Methodology

Materials: Hydrilla verticellata sprigs

3 test tubes

Distilled water

NaHCO3

Phenol red

Procedure: Fill the three test tubes with distilled water and label the A, B, and C. Then, put Hydrilla sprigs into test tubes A and B in an inverted position and add pinches of NaHCO3 to test tubes B and C.

Leave the three test tubes under bright light for about 10 minutes.

Determine if bubble evolution happens to the Hydrilla sprigs in test tubes A and B.

Afterwards, remove the Hydrilla sprigs from test tubes A and B then add five drops of Phenol red to each test tube and shake gently.

Compare the color intensities of the solutions. (Phenol red changes color to yellow)

Results

Bubble evolution, or the releasing of oxygen of the Hydrilla sprig, occurred on both test tubes A and B.

After adding Phenol red to the three solutions, these are the results:

Table 12.3.1 The Role of CO2 in PhotosynthesisSubstance Color Intensities

Test tube A YellowTest tube B Light redTest tube C Dark redResults in Table 12.3.1 show that test tube A was the most basic of the the, considering that no NaHCO3 was added to the solution and test tube C was the most acidic of the three.

Discussion

CO2 is very important to the plant system, because without this it will not be able to produce sugars for the plant and oxygen for us humans in the process of photosynthesis.

In this experiment, we can clearly see from the solution A, B, and C that the plant absorbs CO2 from the solution and releases oxygen back out. The Hydrilla sprigs in test tubes A and B show the occurrence of bubble evolution, which proves that the plant does release oxygen back into the atmosphere.

On another note, when adding NaHCO3 to water, it becomes acidic. Considering this, we can safely say that solutions in test tubes B and C are now acidic. After adding Phenol red to all the solutions, it is seen that solution B is less acidic than solution C. The reason behind this is because the Hydrilla sprig in test tube B absorbed CO2 from the compound NaHCO3, therefore making it less acidic.

This proves our hypothesis that CO2 is essential in the plant system in the photosynthetic process in order to create the necessary sugars for the plant.

References

J. Mauseth, Botany, 2009 Jones and Bartlett Publishers, Inc.