Guided Reading Chapter 7In chapter 6, we learned how our cells obtain and use energy to perform work. This energy was obtained in the form of organic molecules that we as animals obtain from the food that we eat. In chapter 7, we will see how the chemical energy in molecules like glucose is derived from sunlight and why it is that plants are so important to us!1.) Plants don’t eat cookies. However, their cells must also obtain and use glucose to function. What do plants eat?Plants take in CO2 and sunlight2.) Draw a leaf (mesophyll) cell and label a chloroplast, thylakoid, grana, and the stroma. Beside each label, provide a brief description of the item (define whatyou have labeled). Indicate where the light and dark reactions occur in this cell.Chloroplast: (in green plant cells) a plastid that contains chlorophyll and in which photosynthesis takes place.Thylakoid: each of a number of flattened sacs inside a chloroplast, bounded by pigmented membranes on which the light reactions of photosynthesis takeplace, and arranged in stacks or grana.Grana: the stacks of thylakoids embedded in the stroma of a chloroplastStroma: the supportive tissue of an epithelial organ, tumor, gonad, etc., consisting of connective tissues and blood vesselsLight Reaction: the reaction that occurs as the first phase of photosynthesis, in which energy in the form of light is absorbed and converted to chemical energy in the form of ATPDark Reaction: the cycle of reactions (the Calvin cycle) that occurs in the second phase of photosynthesis and does not require the presence of light. It involves the fixation of carbon dioxide and its reduction to carbohydrate and the dissociation of water, using chemical energy stored in ATP.3.) The process of photosynthesis requires gas exchange. How does gas exchangeoccur in the leaf? CO2 is taken up and O2 is releasedIn the light reactions, light energy is transformed into the chemical energy of ATP and NADPH. In this process, electrons removed from H2O pass from photosystem II to photosystem I to NADP+. Between the two photosystems, the electrons move down an electron transport chain and provide energy for the synthesis of ATP.In chemiosmosis, the potential energy of concentration gradient of hydrogen irons (H+) across a membrane powers ATP synthesis. This gradient is created when an electron transport chain uses the energy released as it passes down the chain to pump H+ across a membrane.Using CO2, energy from ATP and high energy electrons from NADPH, the Calvin cycleconstructs energy-rich, three-carbon sugars, glyceraldehyde 3-phophate (G3P)4.) Photosynthesis requires water. How does water enter the leaf? Explain.During the light reaction, water is split, and its electrons are supplied one by one to P680, each replacing an electron lost to the primary electron acceptor.5.) Compare and contrast photosynthesis with cellular respiration. In your explanation talk about CO2, H2O, O2, glucose, oxidation, and reduction.In photosynthesis, CO2 and H2O are taken up and O2 is released. In cellular respiration, O2 and glucose are taken up and CO2 and H2O are released. Bothoxidation and reduction occur. In photosynthesis, CO2 is reduced to glucose and H2O is oxidized to O2. In cellular respiration, glucose is oxidized to CO2 and O@ is reduced to H2O.6.) What happens to the oxygen and hydrogen atoms when water is split in the light reaction? When water is split in the light reaction, the oxygen atom combines with a second oxygen from another split water molecule, forming O2. The exergonic “fall” of electrons provides energy for the synthesis of ATP by pumping H+ across the membrane.7.) The carbon cycle constructs sugar molecules in the stroma from CO2 and energy rich products derived from the light reactions occurring in the thylakoids. Which energy rich products derived from the light reaction are used in the Calvin cycle?The light reactions provide the chemical energy (ATP) and reducing power (NADPH) for the next stage of photosynthesis, the Calvin cycle.8.) In general, where does the mass of a tree come from? (Most college graduatescannot answer this very fundamental
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