First, the data logger is connected to a personal computer. Difference between means = 4.746153846, 3. Also, at higher temperatures the stomata close to prevent water loss. This means that light from lamps other than ours could have affected our experiment, as it means the chlorophyll received a higher intensity than was intended, therefore increasing the rate of photosynthesis. In my experiment I will be measuring the volume of oxygen released from the elodea by shining a lamp to give the elodea light energy needed for photosynthesis to occur. 1. <> ��MU��k�I�f4G��R��ʄ�. 8. To make sure the water is of the correct temperature. endobj ( Standard deviation of the volume of oxygen released at 65oC squared, divided by number of pieces of date = (27.83292436 )2 = 2.120994181, 5. The overall equation is written as: There are two sets of reactions involved in photosynthesis. Pull the bubbles so that they line up with the scale, note down the volume of oxygen released. This also stops gas exchange which slows photosynthesis even further. Light is absorbed by both photosystems and excited electrons are emitted from the primary pigments of both reaction centres (P680 and P700). This may not have been enough time for the experiment to be accurate. The variables that could change the rate of photosynthesis are: Temperature, light intensity, Co2 concentration and amount and type of weed. Repeat procedure, and note down volume of oxygen produced. photosynthesis reaction is taken and which is. they are unable to function properly and the rate of photosynthesis decreases The active site has a specific shape that fits uniquely to the geometric shape of the substrate. plant has different properties for carriyng on photosynthesis like the number At high light intensity, photosynthetic rate levels out, due to other limiting factors, including competition between oxygen and carbon dioxide for the active site on RUBP carboxylase. the problem and selecting the variables. Simple experiments carried out by scientists shows that the rate of photosynthesis is critically dependent upon variables such as temperature, pH and intensity of light. But at high light intensities one or more other factors must be limiting, such as temperature or carbon dioxide supply. The temperatures of the water often varied, therefore we had to add ice and warm water. The square root of the figure calculated in step 5 = 3.475145052. The elodea is cut at a slant, as less air bubbles will be trapped. 9.

The light energy that is absorbed excites electrons in the pigment molecules. At the optimum temperature, the enzyme is most efficient and the rate if maximum. A globe. When the elodea is placed in a water bath of 65oC, I predict the rate of photosynthesis will decrease steeply. This lab report may be a. The proteins are folded into a very particular shape, and this allows them to bind efficiently to the molecules of interest. This is a small difference, therefore the set of results for 0 degrees is very accurate. The elodea was placed in these temperatures and a light shone on them for 5 minutes. This makes the temperature more accurate as less likely the temperature will fluctuate. 17. These days we pollute mother earth very badly and slowly on the globe, there will not be any green left! stream Over the next 15 degrees, as the temperature increases from 15 degrees to 30 degrees, the volume of oxygen goes from 6mm3/min to 28.4mm3/min. During my experiment I will vary one factor, this factor will be temperature. 3. Set a hypothesis for temperature and light intensity. This was very inaccurate as even small amounts of warm water affect the temperature by a large amount. Get a verified writer to help you with Investigating the effect of temperature on the rate of photosynthesis. When the temperature rises, the particles in the reaction move quicker and collide more, so the rate of photosynthesis rises also. The meter was constantly fluctuating therefore it is not completely certain how constant light intensity was in each experiment. Standard deviation of the volume of oxygen released at 35oC squared, divided by number of pieces of data = (11.36500358)2 = 9.935638952, 4. the rate of photosynthesis. When experiment is set up correctly, start the stop clock for 1 minute. This was the rate of oxygen released at 25oC, the average rate of oxygen released for this temperature was 6mm3/min. Therefore this is the closest we could measure the temperature to. During my actual experiment I used 7 different temperatures ranging from 0oC- 65oC. After calculating, percentage To decrease temperature until wanted temperature is gained. I believe my results were quite accurate. As I have shown, the reliability of some results is low; therefore I would do more repeats for these results in particular. Even Work out the means of the two sets of data: 2. During our preliminary experiment, many errors occurred which would affect the accuracy and results of the experiment. In order for photosynthesis to occur, a plant needs a source of … For it to fit exactly on the best-fit curve the average rate of oxygen should be 15.4mm3/min. temperature should be drawn. For the temperature of 35oC the maximum difference between the results for the rate of oxygen released is 6.44mm3/min. This means that the rate of photosynthesis will be at different rates in all experiments, releasing oxygen at rates that are inaccurate. This is because most results are close to the trend line, and both graphs follow the same pattern. The light intensity will be kept the same, by keeping the lamp an equal distance from the elodea in each experiment. This was not very accurate; therefore all experiments should be carried out in a water bath, which will electronically keep the temperature constant. This piece of equipment was the least accurate in our experiment. (235). After At low temperatures the enzymes responsibility for photosynthesis have very little energy so the rate of photosynthesis is very slow. I will repeat the experiment with the elodea in different temperatures to see the affect of this on photosynthesis. down, place the thermometer in water and as soon as you get the expected value, The greater the variation among the individual measurements, the bigger the standard deviation; the less the variation among the individual measurements, the smaller the standard deviation. 1) the variables of light intensity, temperature, carbon dioxide, light quality all influence the rate of photosynthesis. Some of these triose phosphates condense to form hexose phosphates, sucrose, starch and cellulose or are converted to acetylcoenzyme A to make amino acids and lipids. endobj We used thermometers to measure temperature, as it is relatively accurate, to the nearest degree. <> When the elodea has acclimatised for 1 minute, set the stop clock again, and leave for 5 minutes. Samuel Markings has been writing for scientific publications for more than 10 years, and has published articles in journals such as "Nature." On graph 2 the curve of best-fit peaks at 43oC, where the average rate of oxygen released is 41.2mm3/min. This is because light intensity affects the rate of photosynthesis, therefore needs to be kept equal throughout. Photosynthesis defines the process by which plants and some bacte… This could make it inaccurate, as each measurement is accurate to the nearest mm.

As in cyclic photophosphorylation, ATP is synthesised by the ADP getting added to a phosphate group, as the electrons lose energy whilst passing along the carrier chain. This is because as temperature increases above optimum temperature, more bonds break, and the 3D shape changes further, making it less likely for the enzyme and substrate to bind, as the lock and key theory will no longer work. environment should be kept constant and it is going to be done so as the Set up experiment as shown in the diagram, and hold the scale and syringe using a stand and clamp. We collected a class average and did 3 T tests to compare 2 sets of results. This is an increase of 22.4mm3/min, which shows the volume of oxygen increases more rapidly as the temperature increases. This will affect the rate of photosynthesis, as each will have a different total surface area, therefore absorbing different amounts of light. These reactions occur in the grana, and include the synthesis of ATP in photophosphorylation and the splitting of water by photolysis to give hydrogen ions. At very high temperatures this is irreversible.

When carbon dioxide concentration is low less GP can be produced. This has to be done slowly as the bubbles come through fast, therefore if not careful it can go straight to the syringe, therefore the bubbles cannot be measured. Be careful with that; if you need This was not very accurate as bubbles could have been missed. Therefore the whole calvin cycle will be completed at a slower rate. At constant light intensities and temperature, the rate of photosynthesis initially increases with an increasing concentration of carbon dioxide, but again levels at higher concentrations. Light intensity meter (1-10) (not very accurate as lever fluctuates). Therefore I predict more oxygen bubbles will be produced at this temperature. Place a pond weed Elodea upside in a test tube containing water at 25°C. and H20(Water as waist product) with the participation of oxygen (O2) for produces energy. Place the lamp (the only light source) at a fixed distance from the plant.

The temperature peaked at 42oC, after this point the rate started to decrease. This is because during the 5 minutes the elodea was left, the temperature often drifted from what was needed. An assumption being made in this experiment is that the gas bubbles being counted are only oxygen, and that production of oxygen is proportional to the rate of photosynthesis. leaves with sizes and masses that are close to each other should be chosen.