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89 Cards in this Set
- Front
- Back
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What is the definition of photosynthesis?
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plants convert solar energy into energy stored in chemical bonds (chemical energy)
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What is the chemical formula for photosynthesis?
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6CO2 + 12H2O --> C6H12O6 + 6O2 + 6H2O
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What are the two main processes of photosynthesis?
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Light and Dark Reactions
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Are light reactions light independent or light dependent reactions?
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dependent
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Are dark reactions light independent or light dependent reactions?
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independent
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What is the function of a light reaction?
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it uses light energy directly to produce ATP
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What is the function of a dark reaction?
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it usually produces sugars
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How are dark reactions powered?
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by ATP from Light Reactions
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Can dark reactions occur in DARK or LIGHT areas?
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YES!
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Are authotrophs producers or consumers?
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PRODUCERS
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What are two types of authotrophs found in photosynthesis?
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Photoautotrophs and chemoautotrophs
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How do autrotrophs obtain organic food?
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WITHOUT eating other organisms
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Are heterotrophs producers or consumers?
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CONSUMERS
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How do heterotrops obtain organic food?
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BY EATING other organisms or their by-products
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Decomposers count as heterotrophs!
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:)
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What is the function of pigments?
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to absorb certain wavelengths (colors) and reflect all others
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What color are Chlorophyll a and b pigments?
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GREEN
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Chlorophyll a and b absorb what kind of wavelengths?
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wavelengths in the red, blue, and violet wavelengths
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Chlorophyll a and b absord high or low energy wavelenths?
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HIGH
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What color are carotenoid and Xanthiphyll pigments?
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YELLOW, ORANGE, and RED
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Carotenoids and Xanthophyll pigments absord what kind of wavelengths?
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blue, green, and violet wavelengths
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Phycobillin wavelengths are what color?
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Reddish
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What is the function of antenna pigments?
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to capture wavelengths of light not absorbed by chlorophyll a
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What do antenna pigments expand?
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the spectrum of light that can be used to drive photosynthesis
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What are examples of antenna pigments?
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Chlorophyll b and carotenoids
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Antenna pigments absorb light energy, AND..
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pass it to chlorophyll a
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therefore, antenna pigments are directly involved in transforming what into what?
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light E into sugar
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Describe the structure of cholorplasts.
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Outer, double membrane
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What is the site of dark reactions?
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STROMA
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What is the site of light reactions?
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GRANA
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The Grana consists of what? (it increases surface area for reactions)
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stacks of thlyakoid membranes
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What are photosystems?
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light harvesting complexes
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where exactly are the photosystems located?
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in the Grana, in the tylakoid membranes
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how many photosystems are there?
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several hundred per chloroplast
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What do photosystems consist of?
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a reaction center containing chloropyhyl a, AND antenna pigments
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What are the two types of photosystems?
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Photosystem 1 and Photosystem 2
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What is PS1 aka?
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P700
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PS1 absorbs light in what nm range?
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700
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What is PS2 aka?
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P680
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PS2 absorbs light in what nm range?
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680
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What photosystem comes first?
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PS2, then PS1
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In light dependent (LR) reactions, how is light absorbed?
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by PS1 and PS2
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How is ATP Produced in light dependent reactions?
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Exergonic flow of e- through ETC is couples with phosphorylation of ADP to ATP
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What is photolysis?
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when water is split
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Photolysis provides what?
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Electrons for PS2 AND protons to reduce NADP to NADPH
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NADP carries what to Dark Reactions?
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H's
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What is non-cyclic photophosphorylation?
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the main process occuring during light reactions
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Where does non-cyclic photophosphorylation begin and end?
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Begins at PS2, ends at PS1
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What happens during non-cyclic photophosphorylation?
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Electrons from photolysis enter 2 ETCs; ATP and NADPH are formed
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During non-cyclic photophosphorylation, what powers ATP production, and how?
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Chemiosmosis, ATP Synthase
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During non-cyclic photophosphorylation, the NADP reduced to NADPH after H+ does what?
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Diffuses through ATP Synthase channel across the thylakoid membrane
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Cyclic photophosphorylation is --- of non-cyclic.
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MODIFICATION
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What is the function of cyclic photophosphorylation?
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replenishes ATP levels only -- no NADPH is formed
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When does clyclic photophosphorylation occur?
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when the Calvin Cycle uses up available ATP
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Does the Calvin Cycle require little or lots of energy?
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LOTS OF ENERGY!
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During cyclic photophosphorylation electrons travel from where to where?
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from PS2 to PS1, then back again to PS2 (cyclic)
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Where do light independent reactions occur?
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in the stroma
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do dark reactions depend directly on light?
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NO
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What do light independent reactions require?
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Products of light reactions
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What major process do light independent reactions consist of?
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THE CALVIN CYCLE
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What does the Calvin cycle produce?
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PGAL or G3P (same thing)
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What is the LONG name for PGAL and G3P?
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phosphoglyceraldehyde
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what is the primary job of the Calvin cycle?
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Carbon Fixation
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The Calvin Cycle produces PGAL, which is what?
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a 3-carbon sugar
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Where does the Calvin cycle occur?
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In the stroma
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During the Calvin Cycle, CO2 combines with what? and what does it produce?
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combines with RuBP (a 5-carbon molecule) -- produces 2, 3-carbon molecules
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What are an example of 3-carbon molecules?
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C-3 Plants
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The calvin cycle is catalyzed by what enzyme?
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Rubisco (RuBP carboxlase)
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What is photrespiration?
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a dead end process
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What does photorespiration do?
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diverts energy from photosynthesis
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Does photorespiration produce ATP?
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NO
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Does photorespiration produce sugar?
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NO
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How does photorespiration occur?
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When rubisco binds with O2 instead of CO2
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Does rubsico have a greater affinity for CO2 or O2?
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O2!
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What type of plants have adaptation for dry environments?
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C-4 Plants
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C-4 plants are a biochemical and anatomical modification of what?
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C-3 photosynthesis
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C-4 plants involve what?
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Krantz anatomy and Hatch Slack Pathway
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Krants Anatomy refers to what?
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the structure of a C-4 leaf
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Krantz Anatomy minimizes what?
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the time stomates are open
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The Hatch-Slack Pathway precedes what?
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the Calvin Cycle
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What is the function of the Hatch-Slack Pathway?
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it pumps C02 into bundle sheath cells, deep within the leaf
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During the Hatch-Slack Pathway, what binds with C02 to produce MALATE?
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PEP carboxylase
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What is the function of the MALATE pumped into the bundle sheath cells?
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it maintains a steep C02 gradient neat stomates --reduces time stomates need to be opened
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what does CAM refer to?
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Crassulacean Acid Metabolism
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CAM plants are a modification for what?
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dry (xerophytic) environments
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When do stomates open and close in CAM PLANTS?
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open at night, close during day
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In CAM PLANTS, what stores C02 inorganic molecules synthesized at night?
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Mesophyll
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What supplies ATP so the Calvin Cycle can run during the Day in CAM PLANTS?
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Light Reactions
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In CAM PLANTS, C02 is released from organic compounds and synthesized into what?
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Sugars
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