Photosynthesis Experiment By Emily H, Amber V, Chandler M, Rhys, Michael C

Introduction  Photosynthesis is the process that plants use to produce sugar and energy.  The reaction of photosynthesis is sunlight + water + CO 2 (carbon dioxide) equals O 2 (oxygen) and glucose.  We used Swiss chard to test our experiment.  Swiss chard is a plant that is highly perishable.  Its other names are sliverbeet and perpetual spinach.  Looks similar to rhubarb

Research Question  Do different additives in water affect the rate at which photosynthesis occurs within Swiss chard?

Procedure  1.) Obtain materials  2.)Punch 9 disks out of the Swiss chard using leaf punch  3.)Fill 600mL beaker with 500mL of regular tap water  4.) Add in 0.02M of baking soda and stir  5.)Fill 100mL beaker up to 1.8cm with some water from 600mL beaker  6.)Place three disks in syringe (will do this three times for each solution)  7.)Fill syringe half full with water from 600mL beaker  8.) Turn syringe upside down and wait for disks to sink to bottom of syringe. Make sure there is no air bubbles on leaf disk. (may have to shake or push air out)  9.) Once disks have sunk to bottom, remove disks by dumping most of what is in the syringe into 600mL beaker except for a little bit at the bottom with the disks in it  10.)The remaining, dump into the 100mL beaker  11.) Wait for the disks to sink to bottom of the 100mL beaker  12.)Each member should time a disk from the time it touches the bottom until it hits the surface  13.) Record data in seconds, not minutes  14.) Repeat steps 2-13 for 10% solution for sugar water by adding sugar to solution  15.) Repeat steps 2-13 for 10% solution for salt water by adding salt to solution  *use120 volt light as main light source directly above 100 ml beaker while the disks rise*

Hypothesis  If Swiss chard is "watered" with water containing different additives, then photosynthesis will still occur but more slowly than photosynthesis with regular water.

Results

Conclusion  Our hypothesis was not supported. The sugar water and the salt water photosynthesized faster instead of slower than the regular water. We think this happened because sugar is one of the products in the photosynthesis reaction, and because we had that in the water, it did not have to produce as much during photosynthesis, and so it photosynthesis occurred faster. The salt water went faster because there is naturally salt in the soil that plants grow in. We thought that by watering them with salt water, that that was the equivalent of the salt in the soil, which was normal for the plant.

Source accessed on November 17, 2011