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Energy Worksheet True or False – energy moves through a cycle (it is recycled through the environment)
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Energy Worksheet What do plants do with sunlight and what is “life’s universal food”? What group of organisms directly consume plant sugar? What group of organisms use the “leftover” biomass for energy? Define metabolism. Why can there never be more lions than gazelles? Give three reasons we are indebted to plants. What molecules are cycled in a living system?
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Energy Worksheet What two organelles does all life rely on for energy?
What processes take place within these organelles? List the sequence of the real flow of energy through a system. Sugar is important for two reasons. What are they?
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Energy Worksheet What molecules go in? What form of energy goes in?
Organelle What form of energy comes out? What molecules come out?
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Energy and Life Plants and some other types of organisms are able to use light energy from the sun to produce food. Autotrophs – organisms such as plants which make their own food.
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Energy and Life Some organisms cannot use the sun to produce food.
Heterotrophs – obtain energy from the foods they consume.
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Energy and Life Energy comes in many forms such as light, heat, and electricity. Energy can be stored as chemical compounds. One of the principle chemical compounds that cells use to store and release energy is: Adenosine triphosphate (ATP) Basic energy source of all cells
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Energy and Life Storing energy Adenosine diphosphate (ADP)
Releasing energy Adenosine triphosphate (ATP)
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Background of Photosynthesis
When a tiny seedling grows into a tall tree with a mass of several tons, where does the tree’s increase in mass come from? From the soil? From the water? From the air?
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Photosynthesis Van Helmont’s Experiment
Devised an experiment to find out if plants grew by taking material out of the soil. Step 1 Determined the mass of a pot of dry soil and a small willow seedling
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Photosynthesis Step 2 Planted the willow seedling in the pot of soil
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Photosynthesis Step 3 Water it regularly
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Photosynthesis Step 5 At the end of five years Van Helmont weighed the tree and the soil
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What could he conclude with what he knew?
Photosynthesis Results Seedling gained about 75 kg (~169 pounds) Mass of the soil was almost unchanged (weighed 2 ounces less) Conclusions Most of the gain of mass had come from the water because that is the only thing he added What could he conclude with what he knew?
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Photosynthesis Summarize Van Helmont’s experiment in approximately 3-5 sentences. Make sure you include his conclusions!
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Photosynthesis Priestley’s Experiment Step 1
Took a candle and placed a glass jar over it, and watched the flame gradually die out Conclusion Something in the air was necessary to keep the candle flame burning. OXYGEN
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Photosynthesis Step 2 Priestley placed a live sprig of mint under the jar. The candle could be lit and would remain lit for a while
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Photosynthesis Further testing: Conclusion
Priestley discovered that a plant releases a substance that keeps a candle burning and a mouse living. This substance, oxygen, is released during photosynthesis.
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Photosynthesis Summarize Priestley’s experiment in 3-5 sentences. Be sure to include his conclusions!
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Photosynthesis Ingenhousz’s Experiment
Showed that the effect observed by Priestley occurred only when the plant was exposed to light Conclusion: Light is necessary for plants to produce oxygen Summarize Ingenhousz’s experiment in 3-5 sentences. Be sure to include his conclusions!
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Photosynthesis Experiments performed by van Helmont, Priestley, and Ingenhousz led to work by other scientists who finally discovered that in the presence of light, plants transform carbon dioxide and water into carbohydrates, and they also release oxygen.
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Photosynthesis You must know this equation! 6 6 6 CO2 + H2O
Reactants Products 6 6 light 6 CO H2O C6H12O O2 chlorophyll Sugar (glucose) C: H: O: 1 2 3 1 12 8 6 12 18 C: H: O: 6 12 8 6 12 18
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Write this down! Photosynthesis 6 6 6 Cellular Respiration CO2 + H2O
light 6 CO H2O C6H12O O2 chlorophyll Sugar (glucose) Cellular Respiration C6H12O O2 6 6 CO H2O + energy 6 Sugar (glucose)
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Photosynthesis Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into high energy sugars and oxygen.
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Photosynthesis Pigments – substance that absorbs visible light
Most important for photosynthesis: Chlorophyll a – primary pigment Chlorophyll b – collects and passes energy to chlorophyll a Accessory pigments – absorb other wavelengths of light Carotene, xanthophyll, anthocyanin
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Waterweed Simulation
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Photosynthesis Reactants Products
1. Without using notes: write the reactants and products of photosynthesis! Reactants Products _________ + __________ ____________ + _________
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10 minutes to finish and drop!
Waterweed Simulation 10 minutes to finish and drop!
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Waterweed Simulation The affect of light color on the rate of photosynthesis RED BLUE GREEN COLORLESS What color showed the highest rate of photosynthesis? (look at your chlorophyll absorption worksheet) Why?
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Waterweed Simulation 1-10
The affect of light intensity on the rate of photosynthesis 1-10 What light intensity showed the highest rate of photosynthesis? Why?
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Waterweed Simulation 1-10
The affect of carbon dioxide level on the rate of photosynthesis 1-10 What carbon dioxide level showed the highest rate of photosynthesis? Why?
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Photosynthesis Where does photosynthesis take place?
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Photosynthesis Site of photosynthesis: CHLOROPLASTS
Chloroplasts contain: Thylakoids Granum (stacks of thylakoids) Stroma Light Dependent Reactions Light Independent Rxns / Calvin Cycle / Dark Reactions
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Chloroplast Draw this in your notes!
Double membrane, grana, granum, different rxns take place
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What layer of cells contain the most chloroplasts? Why?
Layers of a Leaf What layer of cells contain the most chloroplasts? Why? What is the purpose of the spongy layer, why are there air spaces in between the cells? A. B. C. D. E. F. G. H. Cuticle Upper Epidermis Palisade layer Vein Spongy layer (air spaces) Lower Epidermis Stomata Guard Cells
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Stoma guard cells Stomata open when the internal pressure of the guard cells rises as a result of water absorption. Since the walls of the guard cells are relatively flexible at the side of the stoma, the guard cells expand vertically and the stoma subsequently opens.
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Stomata Open stoma guard cells underside CO2 O2 water vapor water
Closed stoma guard cells Opening formed by two _______________. Found on the _______________ of the leaf. Allow _______ to enter the leaf. Allow _______ and ______________ to exit. Open by filling up with ___________. Conserve water by closing __________. underside CO2 O2 water vapor water at night
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Lilac Leaves Take out your microscope and obtain a lilac leaf cross section. Sketch and LABEL your leaf layers on MEDIUM POWER ONLY! Answer: How does water reach the cells of the leaf? Which layer of cells has the most chlorophyll? THINK ABOUT IT! Where is the chlorophyll located inside the cells? How does CO2 get into the leaf? What regulates the stomata's?
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Photosynthesis occurs in two stages
6 6 light 6 CO H2O C6H12O6 + O2 chlorophyll Photosynthesis occurs in two stages
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Photosynthesis Light Dependent Reactions 4 Major events
Requires light Occur in the grana (where chlorophyll is kept) 4 Major events H2O is split by energy from sunlight Oxygen is released H+ bonds with NADP NADPH ADP + P ATP
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Photosynthesis Light Independent Rxns / Dark Rxns / Calvin Cycle
DOES NOT require light Occurs in the stroma 2 Major events CO2 joins with the H from NADPH to make glucose (C6H12O6) ATP ADP + P
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Photosynthesis Play Extra Credit opportunity DUE MONDAY:
TEN Points if you write a Photosynthesis play.
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Layers of a Leaf A. B. C. D. E. F. G. H. Dark Blue Pink Yellow Orange
Light Blue Opening between green Green
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