Grades 6, 7, and 8
Category – Earth Science
This project focuses on the oil content that is produced in different types of algae. This is done by comparing the beading water droplets on the surface of the algae plants. The goal is for the student to test and hypothesize about the oil production in the specific algae plants used. Useful questions to answer can be, “Which algae produces the most oil?”, “How do algae store the oils?”, and “What conditions allow for better oil production?”.
What you need to know:
Found in most aquatic environments, algae can grow and thrive no matter the state of the water. Multicellular macroalgae grow in fresh water lakes and ponds as well as in the ocean. Unlike pond algae which can be measured in inches, algae that grow in the ocean can grow as long as 100 feet in length. The long algae that grow in the ocean are also known as giant kelp. There are also microalgae that grow in swamps, bogs, and marshes and are quite small. These algae plants are measured in micrometers.
Like most plants, algae require sunlight in order to grow. You can refer to the books on photosynthesis to document how plants grow and add your findings to your presentation. Algae, under normal circumstances, do not produce very much oil unless the plant experiences growth stress. This means that something must happen to deprive the plant of their basic growth requirements. The downfall to starving the plant to produce more oil is that the plant will grow less in mass than under normal growing conditions. This means that for the purposes of oil production, more plants will need to be grown.
When you dry algae in a microwave, the cell walls of the plant are broken down. This allows the oils that are trapped inside the plant to reach the surface. When you place a drop of water on the top of the algae plant, if the water does not sink down into the plant but instead sits on top of the plant in a bead droplet, you know that the oils have all moved up to the surface of the plant.
Algae – (marshes, ponds, swimming pools, swamps, fish tanks)
Filter paper – (science outlets and the internet)
Water dropper – (drug store)
For the first part of your project, you will want to review and learn why and how algae store their oils.
Build a hypothesis that allows you to predict which types of algae contain the most oils.
Collect samples of different algae using your specimen jars. Be sure to collect a little water from each of the sources that the algae are growing in so that your algae will continue to survive during your testing. Do not cross-contaminate your water or algae samples. This is very important. You also want to make certain that you collect both microalgae and macroalgae for your experiment.
Be sure to document the data. Write down where and under what conditions you collected each algae specimen. Make sure that you note whether the conditions were nutrient starved or had an abundance of light.
Choose one of your specimens and divide it into two separate samples.
Using separate pieces of filter paper, place a sample of each specimen on their own piece.
Let the two samples air dry.
On low power, heat one of your samples in the microwave for a short period of time. Be careful that it doesn’t burn! What you are looking to do is to bring the oils in the algae to the surface by cracking the cell walls.
Using your dropper, place one drop of water on the surface of the air dried algae and one drop of water on the surface of the microwave dried algae. Note any differences in what happens to the water droplet. Be sure to record all of your notes.
Repeat this testing on all of your different samples, recording your observations.
Take your findings and write your hypothesis. If needed, revise and retest as is necessary.