The Effect of Light Quantity on Photosynthesis of Green Land Plants
The effect of light quantity on photosynthesis of green land plants
Introduction
Photosynthesis is the process of converting light energy into chemical energy (Hoober 1984). Pigments within chloroplasts, primarily chlorophyll, absorb the incoming solar energy which excites their electrons (Hoober 1984). These pigments exist in photosystems in the thylakoid membrane of the chloroplast (Ladiges et al.2010). As the electrons return to ground level, they are captured by the electron acceptor in the reaction centre of the photosystem (Ladiges et al. 2010). The reaction centre than transfers captured electrons to the electron transport chain (Hoober 1984). The electrons are carried in the form of NADPH, which is then reduced (Hoober 1984). The hydrogen ion produced from this reduction reaction then passes through ATP synthase, generating ATP (Hoober 1984). The chemical DCPIP acts as an electron acceptor and is used to measure the rate of electron transport in the thylakoid membrane of chloroplasts (Dean and Miskiewicz 2006). Initially DCPIP is a blue colour. Although, when it gains electrons from the transport chain it is reduced and turns colourless (Dean and Miskiewicz 2006). A high photosynthetic rate can be interpreted by a fast rate of change from blue to colourless of the DCPIP as more electrons are flowing through the transport chain and reducing the DCPIP. The colour of DCPIP is measured using a spectrophotometer at 605nm.
The rate of photosynthesis is dependent on many factors, in particular light quantity (Johkan et al. 2012). A greater quantity of light received by the chloroplasts equates to a greater amount of solar energy potentially converted into ATP. In turn this causes a higher flow of electrons in the transport chain. The importance of light quantity for photosynthesis is relevant to the growth and harnessing of energy by plants. This can be useful for understanding ecosystems, such as rainforests where the amount of light received by plants is
Introduction
Photosynthesis is the process of converting light energy into chemical energy (Hoober 1984). Pigments within chloroplasts, primarily chlorophyll, absorb the incoming solar energy which excites their electrons (Hoober 1984). These pigments exist in photosystems in the thylakoid membrane of the chloroplast (Ladiges et al.2010). As the electrons return to ground level, they are captured by the electron acceptor in the reaction centre of the photosystem (Ladiges et al. 2010). The reaction centre than transfers captured electrons to the electron transport chain (Hoober 1984). The electrons are carried in the form of NADPH, which is then reduced (Hoober 1984). The hydrogen ion produced from this reduction reaction then passes through ATP synthase, generating ATP (Hoober 1984). The chemical DCPIP acts as an electron acceptor and is used to measure the rate of electron transport in the thylakoid membrane of chloroplasts (Dean and Miskiewicz 2006). Initially DCPIP is a blue colour. Although, when it gains electrons from the transport chain it is reduced and turns colourless (Dean and Miskiewicz 2006). A high photosynthetic rate can be interpreted by a fast rate of change from blue to colourless of the DCPIP as more electrons are flowing through the transport chain and reducing the DCPIP. The colour of DCPIP is measured using a spectrophotometer at 605nm.
The rate of photosynthesis is dependent on many factors, in particular light quantity (Johkan et al. 2012). A greater quantity of light received by the chloroplasts equates to a greater amount of solar energy potentially converted into ATP. In turn this causes a higher flow of electrons in the transport chain. The importance of light quantity for photosynthesis is relevant to the growth and harnessing of energy by plants. This can be useful for understanding ecosystems, such as rainforests where the amount of light received by plants is
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