Costa Photosynthesis Lab Report Ms. Roach AP Biology 4th Period II. Intro/Background 1 . In order for oxygen to be present photosynthesis must occur. Photosynthesis takes in light and CO, and through a series of steps produces oxygen. Photosynthesis can be measured by either the disappearance of substrate or the accumulation of product. Examples include the production of 02 or the consumption of CO. All the oxygen within the leaf disks will be removed before being placed into either of the solutions.
Ill. Question & Hypothesis 1 . What solution will allow the leaf disks to undergo Photosynthesis first? 2. If the cup with bicarbonate solution allows the leaf disk to produce oxygen by the process of photosynthesis then the leaf disk in the bicarbonate solution will be the first to float within the 15 minutes allowed. IV. Methods, Constants, Controls, & Trials 1. A vacuum was created which removed all oxygen from leaf disks 2.
The soap reduced the surface tension on the leaf disks, (which are hydrophobic) and allowed the surface of the leaf to be more permeable to the solutions.
3. The (Oxygen deprived) leaf disks were placed under a light source to mimic the suns effect. 4. Water in this case is the constant in this experiment for the being that it is the only unchanged solution. 5. Leaf disks were monitored for 15 minutes to see if they would float to the top of the solution. 6. 10 Trials were performed for each one of the solutions, giving a grand total of 20 experimental trials.
V. Data Of Disks Time (m) VI.
Analysis/Conclusion 1 . After multiple trials it was concluded that the experiment had not been carried out properly. The water solution was the one which produced floating leafs which contradicted our initial beliefs. The leaves in the bicarbonate solution did eventually float up, following the water. Perhaps not knowing how to correctly transfer the leaf disks into the solution provided a variable which allowed the disks to come into contact with oxygen in the atmosphere.