Light is a very important factor in the rate of photosynthesis, in my project I am going to test that plants do need light in order to photosynthesise.
To that end, they have turned their attention to existing organisms. By studying the molecular details of the reactions that green plants, algae and some bacteria use to photosynthesize, and by analyzing the evolutionary relationships among them, scientists are trying to piece together a cogent historical narrative for the process.
Heliobacteria have perfectly symmetrical reaction centers, use a form of bacteriochlorophyll that’s different from the chlorophyll found in most bacteria, and cannot perform all the functions that other photosynthetic organisms can. For instance, they cannot use carbon dioxide as a source of carbon, and they die when exposed to oxygen. In fact, their structure took nearly seven years to obtain, partly because of the technical difficulties in keeping the heliobacteria insulated from oxygen. “When we first started working on it,” Redding said, “we killed it more than once.”
Some animals are capable of using photosynthesis for short periods of time in order to gain the essential proteins they need to survive. These animals, most living on the bottom of the ocean floor, ingest algae and keep the chloroplasts in their bodies for several months at a time. The chloroplasts allow for photosynthesis to take place so that these animals may live. Animals that are capable of doing this include corals, sponges, sea anenomies, and slugs. It has been discovered, in fact, that slugs possess some of the genes that plants have which allow the chloroplasts to get the proteins that they need. It is even believed that chloroplasts themselves may have started out as a form of symbiotic bacteria that adapted itself to the conditions inside plant cells. Chloroplasts maintain their own DNA separate from the plant's DNA and resembles the DNA of some forms of bacteria.
This process is also affected by the temperature surrounding the plant (the species of plant we experimented with, pond weed, photosynthesised best at around 20 degrees centigrade.) Light, temperature & CO2 are known as limiting factors, and each is as important as the next in photosynthes...
Prediction: I predict that the oxygen bubbles will decrease when the lamp is further away from the measuring cylinder, because light intensity is a factor of photosynthesis.