Does photorespiration have a positive or negative effect on the cell? What is photorespiration and why is it significant? Photorespiration is influenced by high temperature as well as light intensity and accelerating the formation of glycolate and the flow through the photorespiratory pathway. Photorespiration C3, C4, & CAM Plants Photorespiration 1) What normally happens during the carbon fixation step of the Calvin Cycle? C 4 plants have a special enzyme for accepting the atmosphere CO 2.It can accept CO2 even if it lies 1-2 ppm (parts per million) 2. (4pts) Type of Plant Description Example of this type of plant C3 C4 CAM 13. If you heard there was a single factor that reduced the yield of wheat by 20 percent and the yield of soybeans by 36 percent in the United States, for instance, you might be curious to know what it was [1].. As it turns out, the factor behind those (real-life) numbers is photorespiration. RUBISCO enzyme of C 3 plants can't accept CO 2 below 50 ppm, hence photorespiration takes place.. 3. Because carbon is oxidized, the process is termed photorespiration. This is also known as the oxidative photosynthetic, or C 2 photosynthesis or carbon cycle. Our mission is to provide a free, world-class education to anyone, anywhere. First, oxygen is added to carbon. C3 plants do photosynthesis in dry conditions with daytime temperature in range of 40 degree centigrade  and in these conditions,  rubisvo enjyme shows stronger tendency to oxygenate rubp, thus producing 3 phosphoglycerate and 2 phosphoglycolate 2 PG. ADVERTISEMENTS: Respiration that is initiated in chloroplasts and occurs in light only is called photorespiration. Because carbon is oxidized, the process is termed photorespiration. Why photorespiration is considered a loss to C3 plants? Complete the chart on the types of plants that differ in the way they fixate carbon. An important intermediate molecule for carbon dioxide fixation is ribulose bisphosphate (RuBP), and the enzyme catalyzing the CO2 fixation is Rubisco. The enzymes incorporated into the C 4 pathway all have important roles in C 3 plants (Hatch, 1987). In other words, the carbon is oxidized, which is the reverse of photosynthesis—the reduction of carbon to carbohydrate. The problem of photorespiration is overcome in C4 plants by a two-stage strategy that keeps CO 2 high and oxygen low in the chloroplast where the Calvin cycle operates. Photorespiration occurs in hot, dry conditions when the stomata are closed. Photorespiration always competes with the carbon fixing process. Photorespiration plays an important role in the regulation of photosynthetic electron flow under fluctuating light in tobacco plants grown under full sunlight C4 cycle is more efficient than C3 cycle in photosynthesis due to the absence of photorespiration. Desert plants are a great example. Photorespiration is greatly reduced, and CO 2 concentrations in the bundle sheath are maintained at values near what is required to saturate Rubisco. Photorespiration & Plant Adaptations Use the information from these links to answer the questions below. It protects the plants from the photo oxidative damage. Photorespiration is inefficient because it gives off CO2 instead of fixing it, it does not produce any sugars and it wastes ATP and NADPH. What is the importance of photorespiration in plants? This process occurs when there is low CO2, concentration but high O2, concentration. Photorespiration always competes with the carbon fixing process. […] Desert plants are a great example. Email me at this address if my answer is selected or commented on: Email me if my answer is selected or commented on. This happens on hot dry days when a plant is forced to close its stomata to prevent excess water loss. Photorespiration occurs in dry situations, where there is intense light. Photorespiration is also called C 2 cycle as the first main product formed is phosphoglycolate which is a 2 carbon molecule which is later converted to glycolate. Reason If enough C O 2 is not available to utilize light energy for carboxylation to proceed, the excess energy may not cause damage to plants. The reason why C3 over others, it's less expensive than C4 and CAM. Photorespiration reduces the efficiency of photosynthesis for a couple of reasons. It does not produce any energy rich compounds. Privacy: Your email address will only be used for sending these notifications. To log in and use all the features of Khan Academy, please enable JavaScript in your browser. What are the biochemical pathways and structural adaptations (leaf anatomy) that make this possible? (2pts)-12. 9. High crop yields are pretty important—for keeping people fed, and also for keeping economies running. 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