Lab
Kozlowski
Kendal Schweiss
Hour 6
Introduction: Photosynthesis is carbohydrate production using light and chlorophyll. It is a process when green plants and other organisms turn carbon dioxide and water into carbohydrates and oxygen, using light energy trapped by chlorophyll. The rate of photosynthesis can be measured by either the disappearance of substrate or the accumulation of product.
2H2O + CO2 + light -> carbohydrate (CH2O) + O2 + H2O There is a spongy mesophyll layer in leaves, or disks of leaves. It is normally infused with gases, making the leaves normally float in water. If the leaf is put in a solution with an alternate source of carbon dioxide, then photosynthesis can occur in sunken leaves. Nevertheless, there are variables that can affect the rate of photosynthesis when doing so.
Hypothesis: If two different color pieces of cellophane is placed on the top of a cup of sunken disks of spinach leaves, then the rate of photosynthesis will be faster in the cup covered with green cellophane.
Materials:
* Baking soda (sodium bicarbonate) * Liquid soap * 2 Plastic syringes * Living leaves * Hole punch * 2 clear plastic cups * Timer * Light
Experiment: First, bicarbonate solution was prepared and poured into two clear plastic cups to a depth of about 3 cm. Then, one drop of liquid soap was dropped into the solution in each cup. Using a hole punch, 10 spinach leaf disks were cut out for each cup. Each set of leaves were placed into two separate syringes. The plunger was replaced into the syringes and pushed in until only a small volume and air and leaf disked remained in the barrel (without damaging the leaf disks). Then, a small volume of the sodium bicarbonate plus soap water was pulled into the syringe. The plunger was then pulled even farther back, with one finger on the opening of the syringe, creating a vacuum. It was held for about 10 seconds and then released. This was done until