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Regents Review: Photosynthesis and Respiration Define the following terms: SEE YOUR GLOSSARY IN YOUR REVIEW BOOK ATP – Cellular Respiration – Chloroplast – Gas Exchange – Glucose – Guard Cells – Homeostasis – Mitochondria – Photosynthesis – Respiration – What are the basic needs for plant growth? Carbon Dioxide (CO2), Water (H20), Light Photosynthesis is the conversion of light energy into chemical energy What is the difference between autotrophic nutrition and heterotrophic nutrition? Autotrophs can make their own food (energy) Heterotrophs need to eat food to obtain energy What are the two types of autotrophs? Photoautotrophs - use light energy to make food (ex. Green plants, algae) Chemoautotrophs - use inorganic chemicals to make food (Ex. mostly bacteria) What are the photosynthetic pigments? Which is the most abundant? Chlorophyll a & b (green) – most abundant Carotenes (orange) Xanthophylls (yellow) What process is associated with a chloroplast? What is a chloroplast made of? Photosynthesis. Contains: photosynthetic membranes arranged in flattened sacs called thylakoids, stacks of thylakoids are called grana, regions between the grana are known as stroma Why cant we just use chlorophyll alone to produce glucose? What else do we need? It only absorbs certain amounts of light energy so we need multiple pigments. Also, it doesn’t convert this absorbed energy into chemical energy alone, we need the proteins in the thylakoid membranes. Describe how guard cells regulate homeostasis within the stomates: Regulate the opening and closing of stomates (caused by osmosis with in the two guard cells). They are closed when little water is available, at low temperatures or when little light available and will open when the leaf needs to release extra water, at high temperatures or when there is enough light available. What is the overall chemical formula for photosynthesis? (light) 6 CO2 + 12 H2O C6H12O6 + 6 O2 + 6 H2O Carbon dioxide + water + light Glucose + oxygen + water Label the layers of a leaf cross-section below? What does each layer do/contain? 1. Outermost layer is a clear waxy cuticle that protects inner tissues and slows down water loss from leaf 2. Epidermis is below cuticle, contains no pigment, protects inner tissues, contains stomates (small openings on the underside of the leaf that allow the exchange of carbon dioxide, oxygen and water vapor between the leaf and the environment) 3. Palisade mesophyll is a tightly packed 1-2 cell thick layer filled with chloroplasts, site of photosynthesis 4. Spongy mesophyll has irregularly shaped cells and large air spaces in between cells (stomates located near this layer to allow for gas exchange) with fewer chloroplasts found here 5. Vein contains xylem (to transport water/mineral) and phloem (to transport food/materials) What is the difference between the light and dark reactions? Light dependent reactions produce ATP that the light- independent reactions use to make glucose What is Chemiosmosis? Movement of H+ ions through ATP synthase proteins within the thylakoid membrane to take ADP + P ATP (to produce energy for the cells to use) Photosynthesis converts inorganic materials (H2O, CO2, light) into organic molecules (C6H12O6) What factors affect photosynthesis: Light intensity, temperature, water availability, mineral availability, pH, CO2 availability What does cellular respiration break down to form energy? Energy (e-) is released from the breakdown of glucose and used to combine ADP + P to form ATP Where do organisms obtain the raw materials needed? From the food they digest (heterotrophs) or create themselves (autotrophs) Does it occur in autotrophs and heterotrophs? Yes in both What organelle is associated with cellular respiration? Mitochondria What process transfers energy from one molecule to another? Electron transport chain Is the high-energy molecule ATP or ADP? What are the two types of cellular respiration? Anaerobic and aerobic respiration. Which requires oxygen? Aerobic. Which produces the most energy by the complete breakdown of glucose? Aerobic. What is glucose broken down into? Two pyruvic acids Describe the process of glycolysis? Does it occur in both types of respiration? How much energy is produced? Splitting of glucose (6-carbons) into two pyruvic acid molecules (3-carbons) which occurs in the cytoplasm. Occurs in both types and produces 4 ATP total for each glucose molecule. Describe fermentation and what are the end products of fermentation in yeast and bacteria? Pyruvic acid is changed into other compounds. In yeast it makes ethyl alcohol and carbon dioxide. In bacteria it makes lactic acid. Where does pyruvic acid breakdown? Within the mitochondria on the surface of the inside membrane What is the net overall output for each glucose molecule in the Kreb’s cycle? For each glucose molecule, it takes two turns of the Kreb’s cycle, producing 1 ATP for each cycle producing a total of 2 ATP for each glucose molecule How many ATP molecules does the electron transport chain produce? Where does this occur? Produces 32 ATP for each glucose molecule. Occurs within the mitochondria across the inner membrane. What is the overall net reaction of cellular respiration? C6H12O6 + 6 H2O + 6 O2 6 CO2 + 12 H2O + 36 ATP Glucose + Water + Oxygen Carbon Dioxide + Water + Energy Why does muscle fatigue happen in our bodies? During prolonged periods of physical activity, the muscle cells use oxygen faster than it can be supplied (shuts down Krebs cycle). Muscles then continue to release energy by glycolysis. Pyruvic acid is converted to lactic acid which can build up causing muscle fatigue Can other organic molecules be used, like proteins or fats? Yes Regents Review Questions 1. All life depends on the availability of usable energy. This energy is released when 2. The rate at which all organisms obtain, (1) organisms convert solar energy into the transform, and transport materials depends chemical energy found in food on an immediate supply of molecules (1) ATP and enzymes (2) respiration occurs in the cells of (2) solar energy and carbon dioxide producers and high-energy molecules (3) carbon dioxide and enzymes enter the atmosphere (4) ATP and solar energy (3) cells carry out the process of respiration (4) animal cells synthesize starch and carbon dioxide 3. A five-year study was carried out on a 6. The graph below shows photosynthetic population of algae in a lake. The study activity in an ecosystem over a 24-hour found that the algae population was steadily period. decreasing in size. Over the five-year period this decrease most likely led to (1) a decrease in the amount of nitrogen released into the atmosphere (2) an increase in the amount of oxygen present in the lake (3) an increase in the amount of water vapor present in the atmosphere (4) a decrease in the amount of oxygen released into the lake Data for a study on respiration in this ecosystem should be collected during (1) interval A, from only the producers in the ecosystem 4. The diagram below represents a (2) intervals A and B, from only the biological process. consumers in the ecosystem (3) intervals A and B, from both the producers and consumers in the ecosystem (4) interval A only, from abiotic but not Which set of molecules is best represented biotic components of the ecosystem by letters A and B? (1) A: oxygen and water B: glucose 7. A student studied the location of single- (2) A: glucose celled photosynthetic organisms in a lake for B: carbon dioxide and water a period of several weeks. The depth at (3) A: carbon dioxide and water which these organisms were found at B: glucose different times of the day varied greatly. (4) A: glucose Some of the data collected are shown in the B: oxygen and water table below. 5. The diagram below represents a cross section of part of a leaf. A valid inference based on these data is that (1) most photosynthetic organisms live below a depth of 150 centimeters (2) oxygen production increases as Which life functions are directly regulated photosynthetic organisms move deeper in through feedback mechanisms associated the lake with the actions of the structures labeled X? (3) photosynthetic organisms respond to (1) excretion and immunity changing light levels (2) digestion and coordination (4) photosynthetic organisms move up and (3) circulation and reproduction down to increase their rate of carbon (4) respiration and photosynthesis dioxide production 8. The relative amount of oxygen in the atmosphere of Earth over millions of years is shown in the graph below. At what point in the history of Earth did autotrophs most likely first appear? (1) 3500 million years ago (3) 1500 million years ago (2) 2500 million years ago (4) 500 million years ago Untreated organic wastes were accidentally discharged into a river from a sewage treatment plant. The graph below shows the dissolved oxygen content of water samples taken from the river at specific distances downstream from the plant, both before, and then three days after the discharge occurred. 9. Explain why an energy-releasing process occurring in the mitochondria of the decomposer organisms is most likely responsible for the change indicated by the data shown at sampling site C in the graph. At site C oxygen is being used by the mitochondria of the decomposer to break down glucose molecules to form ATP (energy) by the process of cellular respiration to use for the organisms various life processes. In recent years, the striped bass population in Chesapeake Bay has been decreasing. This is due, in part, to events known as “fish kills,” a large die-off of fish. Fish kills occur when oxygen- consuming processes in the aquatic ecosystem require more oxygen than the plants in the ecosystem produce, thereby reducing the amount of dissolved oxygen available to the fish. One proposed explanation for the increased fish kills in recent years is that human activities have increased the amount of sediment suspended in the water of Chesapeake Bay, largely due to increased erosion into its tributary streams. The sediment acts as a filter for sunlight, which causes a decrease in the intensity of the sunlight that reaches the aquatic plants in the Chesapeake Bay ecosystem. 10. Identify the process carried out by organisms that uses oxygen and contributes to the fish kills. Cellular Respiration 11. State how a decrease in the amount of light may be responsible for fish kills in the Chesapeake Bay area. The decrease in the amount of light will limit the resources the plants need to convert carbon dioxide, water and light into glucose and oxygen which is used by the fish and other oxygen-consuming organisms within the bay. A decrease in light will limit the production of oxygen being released through photosynthesis of the bay’s plants.
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