Students should be thinking about the question they will raise about the photosynthesis experiment and if an investigation can be designed to test their question.
Read a full protocol on how to investigate photosynthesis using pondweed. The test tube can be inverted and the air pocket can be measured.
Temperature range at which optimum photosynthesis can occur, varies with the plant species. You can then investigate the amount of gas produced at different distances from a lamp. Lines of best fit were drawn for each CO2 concentration to make up for any inaccuracy in any individual result.
At temperatures over 40oC enzymes involved in the process are increasingly destroyed, so photosynthesis slows down and eventually stops because the photosynthesis enzymes are destroyed. This would have increased the rate of reaction of the plant's enzymes which would have increased the photosynthesis rate.
A thermostated water bath would be ideal. All students will be guided to use this technique. Since the graph line has become horizontal flattened outthis also means that carbon dioxide concentration is no longer the limiting factor - you must increase light intensity or temperature to increase the rate of photosynthesis.
Repeating this experiment while varying different factors would allow for the determination of optimal growing conditions of spinach leaves. The leaves were submerged in solutions of NaHCO3 which were placed under the lamps.
Again fix up the apparatus afresh and now instead of adding any substance or covering the bubbler with coloured papers, keep it near the electric heater. By using a different piece of elodea for each experiment did create the problem of it being impossible for each piece to have the same surface area.
Water will not be a limiting factor as the plants are living in water. A written exam will be used to determine if a student has met the goals of the activity. If you harvest several plants and record how much mass they have accumulated you will have an accurate measure of the surplus photosynthesis over and above the respiration that has taken place.
It might ok just to measure the speed of bubble down the capillary tube, BUT what happens if it fills with oxygen gas - you won't see any movement See method 3 next. They affect the dark reactions. Some was used by small invertebrates that were found living within the pieces of elodea.
BUT, for maximum effect you need a warm temperature, plenty of light and extra CO2 if you can supply it! So, red wavelength is most effective, the blue wavelength comes next in order and the green is least effective.
This is shown by the graph line becoming horizontal, and the maximum rate is now dependent on the temperature ie the higher the temperature the greater the maximum rate of photosynthesis possible. As predicted when the NaHCO3 concentration is increased the plant in able to get more CO2 which causes the rate of reaction to go up.
Incandescent light bulbs provided the light source for leaf segments to undergo photosynthesis. Thus, the spinach segments were first made to sink by subjecting a mixture of the leaves and 0.
Doing this could lead to being disqualified from all the subjects that you are taking. The chlorophyll is removed. If you want more help with doing your biology practicals then have a look at 'Advanced Level Practical Work for Biology' by Sally Morgan.
However, you can probably think of several inaccuracies in this method. The curve on the graph does however level out quite soon showing that the rate is being limited by the lack of NaHCO3 in the water.
You can use sodium hydrogencarbonate NaHCO3 as source of carbon dioxide and vary its concentration to vary the carbon dioxide concentration. Clearly, CO2 is the limiting factor.photosynthesis, however, does not happen all the time, and when it happens depends on a number of environmental factors.
For example, plants need a supply of water, carbon dioxide, and light. As light intensity increases, the rate of photosynthesis will increase as long as other factors are in adequate supply.
light is again a limiting factor and a higher rate can be reached before the rate again plateaus. increasing temperature will have the greatest effect on reaching a higher rate of photosynthesis. Finding out How might. This activity will allow students to measure the rate at which the photosynthesis process occurs.
Students will work in small groups to design an experiment with one independent variable and test this variable on spinach leaf disks. A brief outline of various ways to measure the rate of photosynthesis - including measuring photosynthesis via the uptake of carbon dioxide (e.g.
using immobilised algae), via the production of oxygen in pondweed, via the increase in dry mass, and via the production of carbohydrates. The students can be allocated to investigate a particular factor that affects the rate of photosynthesis, or they can choose from this list, or they can develop their own ideas.
Light intensity or distance of the Elodea from the lamp. The reactions of photosynthesis can be divided into two major types: light-dependent reactions and light-independent reactions. The light-dependent reactions convert energy from the sun into a form that the chloroplast can then use to make sugar from carbon dioxide, in the process producing oxygen as a .Download