Biology Photosynthesis – Flashcards
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What does ATP stand for? Where is energy stored in molecules? ATP? How can ATP be compared to a battery?
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Adenosine-triphosphate. Energy is stored in ATP in molecules by the ability of one of the ATP's phosphates being able to break off and bond with another molecule, causing that other molecule to become unstable and change. ATP is similar to a battery because it can be "recharged" from ADP bonding to another phosphate, and it also is a form of chemical energy.
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Explain how ATP synthase works
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ATP synthase uses the energy from hydrogen ions moving through the enzyme down their concentration gradient by diffusion to stick phosphates onto ADP and make ATP
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Write out the equation for photosynthesis. Where does the oxygen gas come from? Where does it go?
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The oxygen comes from the water molecule being broken up to replace the electrons in photosystem II. It goes out through the stomata
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What is the difference between an autotroph and a heterotroph? Give examples of each. How are the two related?
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Auto - self
Hetero - other
Autotrophs produce their own food for energy, while heterotrophs get their energy from others. Autotrophs are things like plants, while heterotrophs are things like animals. Heterotrophs eat autotrophs very often for energy.
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What are the pigment molecules found in most leaves? What is the purpose of these pigments? Give an example of another organism besides plants that utilizes pigments.
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Chlorophyll. They absorb certain wavelengths of light that a plant can use more effectively in photosynthesis. Humans also have pigmentation called melanin
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What color wavelengths of light do autotrophs absorb best? Which wavelength is shortest? Is this high energy of low energy?
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Autotrophs absorb blue/purple and red best. Purple is the shortest wavelength of visible light. It has a high energy.
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Would a plant grow better in blue light or yellow light? Explain why.
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Blue light because it can absorb blue light better and reflects yellow and green light
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Why do leaves change color in the fall?
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The chloroplast in the leaves stop needing to absorb red light
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What does the energy from the sun allow proteins embedded in the thylakoid membrane to do?
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It allows electrons to be moved around the photosystems and electron transport chains
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List the substrates and products of the light-dependent reaction
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H2O + NADP+ + ADP (and phosphates) ---Sunlight---> H+ + O2 + NADPH + ATP
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List the substrates and products of the Calvin Cycle
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CO2 + NADPH + ATP ------> G3P + NADP+ + ADP (and phosphates)
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What molecules are recycled in photosynthesis?
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ATP and NADPH
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When does carbon dioxide get fixed into sugars?
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In the Calvin Cycle
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Distinguish between RuBP and Rubisco
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Rubisco is the enzyme that bonds CO2 to RuBP.
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What does the Calvin cycle need from the light-dependent reaction in order to make sugar?
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ATP and NADPH
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What are some factors that affect the rate of photosynthesis?
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The amount of sunlight available, the type of visible light that is in the sunlight, the amount of CO2 in the air, the amount of H2O that the plant has access to
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What is a photovoltaic cell? How is it similar to a plant performing photosynthesis? How is it different?
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A solar panel. It changes sunlight into another form of usable energy. It doesn't need any other molecules, and it turns sunlight into electricity, not sugar
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How are photosynthesis and cellular respiration related?
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They are opposite reactions from each other, so THEY FORM A CYCLE
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What is the function of stomata? How do they open and close? How do stomata help maintain homeostasis for a plant?
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They allow materials to pass in and out of the plant. They open close using guard cells to regulate what goes in and out of the plant.
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How have some plants evolved to deal with higher temperatures? Explain how their mode for producing sugars is different than a C3 plant.
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Some plants produce four-carbon molecules before they produce 3-carbon molecules to fix the carbon, and are called C4 plants. It allows the plant to keep their stomata partially closed and prevents water loss because they have an enzyme that grabs carbon dioxide better than rubisco
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Explain how plants adapt to changes in the level of CO2 in the atmosphere.
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They evolve to have fewer stomata if there is more CO2 and more stomata if there is less CO2.
