The Dark reaction of photosynthesis is purely enzymatic and it … Requires CO2 a. both the light reactions and the Calvin cycle b. occurs in the chloroplast but is not part of photosynthesis c. light reactions alone d. neither the light reactions nor the … Eukaryotes like plants and green algae contain membrane bounded organelles which aid them to perform photosynthesis. The dark reac-tions also constitute a redox process, since the carbon in carbohydrates is in a more reduced state than the highly oxidized carbon in CO 2. The chemical processes of photosynthesis occurring independent of light is called dark reaction. It takes place in the stroma of the chloroplast. ATP and NADPH 2 is formed during the dark reaction which is utilized for fixation of carbon during the dark reaction. Transfer of energy from antenna chlorophyll to reaction center chlorophyll to excite photosystem 2 reaction center c) What is the path of electrons in the Z-scheme? The two successive stages in which photosynthesis takes place are: The Light-dependent reactions; The Calvin Cycle, or the light-independent reactions; Let’s have a detailed look at these stages: The Light-dependent Reactions. Please enable Cookies and reload the page. In the dark reactions, the ATP and NADPH produced in the light reaction provide the energy and reducing power for the fixation of CO 2. The carbon dioxide is fixed to carbohydrates using the energy molecules like NADPH2 and ATP. The chemical processes of photosynthesis occurring independent of light is called dark reaction. Dark reactions can take place can take place 24-hours a day. Photosynthesis is the food making process done by the organisms possessing chlorophyllous cells. As the light reactions happen at the initial stage, they produce the complementary products that are further used in the next phase, which is a light independent phase (dark reactions). Cloudflare Ray ID: 62608cc08f6a2739 Dark reactions make use of these organic energy molecules (ATP and NADPH). As their name suggests, the light reaction is the initial phase of the process of photosynthesis, and it requires light, whereas dark reaction is the later phase of the process of photosynthesis and it doesn’t require light energy. Chloroplasts are organelle present in plant cell that serves as the main site for photosynthesis. This phase requires sunlight. Chlorophyll absorbs the red and blue segment of the white light and photosynthesis occurs most efficiently at these wavelengths. Questions on Light Reactions a) In which specific part of the chloroplast do the light reactions take place? Dark reaction is the later phase of the process of photosynthesis and it doesn’t require light energy. Light reactions take place in chloroplasts’ thylakoid membranes in a leaf. In dark reaction in photosynthesis, C3 pathway is noticed in green plants and C4 pathway is observed in desert plants. The Calvin cycle, light-independent reactions, bio synthetic phase, dark reactions, or photosynthetic carbon reduction (PCR) cycle of photosynthesis are the chemical reactions that convert carbon dioxide and other compounds into glucose. Photosynthesis takes place in … The Steps Involved in the Light Reaction. Following is the fundamental equation of photosynthesis 6CO 2 + 6H 2 O (+ light energy) → C 6 H 12 O 6 + 6O 2. It takes place in the stroma of chloroplast. In light reaction, the photolysis of water is done, and the energy molecules like NADPH2 and ATP are formed, whereas in dark reaction reduction of the carbon takes place using the light reactions energy products NADPH2 and ATP. Dark reaction utilizes ATP and NADPH energy molecules coming from the light reaction of photosynthesis for the regeneration of RuBP and carbohydrate synthesis. Light-independent reaction is also called the dark reaction or the Calvin cycle. Janet White is a writer and blogger for Difference Wiki since 2015. Photosynthesis has two sets of reactions - the light reactions and dark reactions. We do not implement these annoying types of ads! The sugar molecules are synthesized using the carbon dioxide molecules. In light reaction, the photolysis of water is done, and the energy molecules like NADPH2 and ATP are formed. Please add difference.wiki to your ad blocking whitelist or disable your adblocking software. Light reactions take place in the grana of the chloroplast. We've detected that you are using AdBlock Plus or some other adblocking software which is preventing the page from fully loading. Photosynthesis takes place through several steps which occur during two stages: the light phase and the dark phase. Photosynthesis process is a kind of the reverse of the process of respiration that takes place in each and every of the organism. The chemical energy acquired during the light reaction fuels the second phase of photosynthesis. These light-independent reactions are also known as the dark reactions (because light is not a reactant) or the Calvin Cycle. Light and dark reactions in photosynthesis. She has a master's degree in science and medical journalism from Boston University. Unlike this, the dark reaction can take place at night time. Oxygen is produced as a result of the chemical process. Dark reactions Dark reactions (Enzymatic reactions) is a group of reactions that occurs in the stroma of chloroplast in which the temperature is the limiting factor for the rate of photosynthesis, so, these reactions can occur in both the light and darkness. As mentioned above, carbon dioxide is taken in through the stomata of the plants and moves to the stroma of the chloroplast. All the significant reactions of photosynthesis process generally take place during day time in the chloroplasts of leaves. 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