Prediction : I predict that as I increase the distance between the light source and the Canadian Pondweed (reducing the light intensity), the volume of oxygen produced within the time limit (the measure of the rate of photosynthesis) will decrease.
Hypothesis:Photosynthesis is a process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose....
The result of two light reactions is a total of six oxygen molecules (6 O2) released into the air as byproducts and 12 NADPH2 (24 H) carried over to the dark reaction of photosynthesis....
We have also learnt that photosynthesis is a vital process that occurs in order to create glucose and oxygen, by transforming carbon dioxide and water in the presence of light energy.
Implications of these tests:
This controlled test has aquatic implications, as photosynthesis is the same whether it be a terrestrial plant, a freshwater aquatic plant, or symbiotic zooanthellic algae found in corals.
The main difference would be that light energy is quickly absorbed by water, especially red light waves and many modern high-end LED fixtures such as an EcoTech Radion, AI Sol Vega Blue, ZetLight ZT 6600, AAP Fiji Blue, AAP Ocean Blue NP, and AAP Reef White 2000 produce the light energy for deeper aquarium water penetration more comparable to the popular 20k "Radium" Metal Halides.
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...
Background information: Photosynthesis Photosynthesis is the process of autotrophs turning carbon dioxide and water into carbohydrates and oxygen, using light energy from sunlight.
For photosynthesis to occur, plants need: · Light energy from the sun · Chlorophyll to absorb light energy · Carbon dioxide from the atmosphere and from respiration in plant cells · Water which is absorbed by the roots and transported to the leaves by the xylem tubes....
Furthermore, I predict that if the light intensity increases, the rate of photosynthesis will increase at a proportional rate and more oxygen will be produced and therefore the oxygen levels will increase.
My reason for believing this
is that as mentioned previously, light is one of the limiting factors
required for photosynthesis, and by lowering the amount of light
available to the plant, I will be decreasing the rate at which the
process of photosynthesis takes place in the plant.
I think this because the plant may use up all of the carbon dioxide (Sodium hydro carbonate) and the plant can have as much light as it needs but if it does not have any carbon dioxide it will not be able to photosynthesise....
Now we generally will start with the the PAR for what we intend to utilize our lights for (although many will often use higher PAR readings than necessary).
Even then with the many LEDs available, we need to look at input energy versus output energy since often the same input in watts (joules of energy) can have a different output in PAR due to wasted heat energy in drivers, controllers, fans, etc. In fact these efficiencies just within LED light can vary greatly with some as efficient as .08 watt per mm of PAR (one model of AAP AquaRay) & as inefficient as 2.7 watt per mm of PAR (a Beamsworks LED).
Then we get to the QUALITY of the light output as per the application & this too can vary, even with the same PAR output (photons of light), meaning one light with the same PAR reading can be superior over another.
providing the plant with a greater intensity of light, I will be
enabling the plants' process of photosynthesis to take place more
intensively, as the factor required (in this case light) is available
at a greater quantity.
Moroney JV and Somanchi A (1999) How do algae concentrate CO2 to increase the efficiency of photosynthetic carbon fixation? Plant Physiology 119: 9–16.