Lab Report: Production of Oxygen by Photosynthesis

Objectives:

To demonstrate the plant biology of interactions with the carbon cycle using sunlight.

To discover how plants generated our current atmosphere that allowed animal life to persist.

Purpose:

The purpose of this experiment is to demonstrate the carbon cycle in action, by producing oxygen via photosynthesis.

Hypothesis:

If the weight of an Elodea plant increases, then the amount of oxygen produced will also increase.

Materials:

The materials required for this laboratory experiment include:

One (1) 1,000 ml beaker

One (1) glass funnel

One (1) glass tube,

Water

An aquatic plant, which, for the purposes of this experiment will be three (3) to five (5) strands of Elodea.

Procedure:

The procedure to be followed for successful completion of the experiment is as follows:

Fill the 1,000 ml beaker 2/3 full with tap water.

Place the Elodea plant at the bottom of the beaker.

Place an inverted funnel over the plant.

Place a test tube over the funnel tip, making certain that the test tube is completely filled with water.

Label your beaker.

Place the set up on a tray, to be placed in direct sunlight.

In one week, estimate how much oxygen has been produced per weight of the plant.

(Figure 1 omitted for preview. Available via download)

Objectives:

To demonstrate the interaction of microorganisms with the carbon cycle using yeast, sugar, and water.

To discover how organisms are dependent on water and energy flow through some type of food chain.

Purpose:

The purpose of this experiment is to demonstrate the carbon cycle in action, by producing ethyl alcohol using the process of fermentation.

Hypothesis:

If the amount of sugar added to the fermentation process is increased, then the level of ethyl alcohol yielded will also increase.

Materials:

The materials required for this laboratory experiment include:

Four (4) quart-sized Ziploc bags

Four (4) packets of activated dry yeast

One and three-fourths (1 ¾) teaspoons of sugar

One (1) teaspoon measure

One (1) cup measure, six (6) cups of warm water

One (1) large water bath, one (1) marking pen

One (1) thermometer, cardboard, and a ruler.

Procedure:

The procedure to be followed for successful completion of the experiment is as follows:

Pour one packet of activated dry yeast into each of your four Ziploc bags.

Add one teaspoon of sugar to one bag and label it “one teaspoon.”

Add ½ teaspoon of sugar to a second bag and label it “1/2 teaspoon.”

Add ¼ teaspoon to a third bag and label it “1/4 teaspoon.”

Label the final bag without sugar “0 teaspoons.”

Set up the water bath so that it is approximately ¾ of the way full.

Check the temperature and adjust it to the desired range (115º F) using hot or cold water.

Use the measuring cup to transfer ¼ cup of warm water from the bowl to each bag. Mix the contents thoroughly, making sure there are no pockets of dry yeast or sugar in the bag.

Squeeze the air out of the bags and seal them. Set them into a water bath to incubate.

Wait 40 minutes.

Take the bag marked “0 Teaspoon” out of the water, dry the bag and place it on a flat table. Put the cardboard or notebook on top of the bag and hold it level. Use the ruler to measure the distance from the table to the bottom of the cardboard. Record your direct measurements.

Repeat the previous step for the three remaining bags.

Calculate the approximate volume of carbon dioxide in each bag. You know the bag dimensions by measuring the length, the width, and the height.

(Figure 2 omitted for preview. Available via download)

Conclusions:

The stated hypothesis regarding the production of oxygen via photosynthesis was, “if the weight of an Elodea plant is increased, then the oxygen (O2) production of said plant will also increase.” This hypothesis was proven correct over the course of the experiment, with figure 1 showing the gradual rise in plant weight having a positive correlation on the production of oxygen in a given plant. The stated hypothesis regarding the production of carbon dioxide (CO2) via the process of fermentation was, “If the amount of sugar added to the fermentation process is increased, then the level of ethyl alcohol yielded will also increase.” This hypothesis was also proven correct, with figure 2 showing the increase in added sugars to the yeast mixture yielding an increase in the total volume of carbon dioxide given off by the fermentation process. The positive correlation of variables across both experiments shows the consistency of biological energy cycles, offering a glimpse of what makes a system: The output will always increase with, but never exceed, the input. Just as sunlight creates a chemical reaction within the Elodea to create oxygen in photosynthesis, sugar chemically reacts with yeast and water to create carbon dioxide in fermentation following the same cycle. The Earth as a whole follows this cycle as well, and the daily interference of synthetic carbon dioxide has thrown the system off balance entirely. However, synthetic carbon dioxide emissions are only the tip of the iceberg; in order to mitigate the damages done by human interference, much more than curbed CO2 emissions is needed. The addition of new types of flora and fauna via genetic engineering is also a threat to the balance of entire ecosystems. Going forward, human understanding of bio- and geochemical cycles is crucial if human society wishes to undo the damages already wrought and evade the worst of the damages still to come. The laboratories presented in this report are prime examples of the types of cycles that permeate the entirety of Earth’s ecosystem and serve as accurate case studies of how such cycles react in nature.

Works Cited

"Microorganisms and the Carbon Cycle Laboratory." Environmental Biology BIOL 112 (2014): 8. Print.

“Photosynthesis and the Carbon Cycle Laboratory.” Environmental Biology BIOL 112 (2014): 8. Print.