1/19/11 Juliana Ruta Period 8 blog number 4

Today in class we started our photosynthesis experiment.

To set up the experiment one person had to measure the mass of the carbon dioxide tablet. If you were in the high amount group you had to get a piece weighing from 1-1.5. If you were in the medium amount group you needed a piece that weighed 0.5-1. If you were in the low amount group you needed a piece that weighed from 0-0.5. After you got the right amount you had to crush up the tablet. While someone was doing that, someone else was getting the elodea plant and getting rid of the leaves near the stem and crushing it at the bottom. A third person was getting the water. We used 20 ml of water which we measured with a graduated cylinder. Then we poured the water into a test tube.
For the experiment, the first thing to put into the test tube was the water. Next we put in the CO2. Before you add the elodea, you have to wait for the bubbling to settle down. Once it does you can put in the elodea and start your timer. Start counting the bubbles you see come off the plant. After a minute, record your results. Keep doing this after each minute until 5 minutes has passed.

Not a lot of people were able to complete the experiment. Some of the parts that confused people were for the high carbonated water was the plant kept floating up to the top so they should use 1.1 instead of 1.4 or 1.5. Another problem was people counted the wrong bubbles so they got the wrong numbers. We will do the experiment again tomorrow.

Here is a link to a video of an elodea plant during photosynthesis-

http://www.youtube.com/watch?v=QCDRq6u8tCg


JR Period8