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42 Cards in this Set
- Front
- Back
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What is photosynthesis?
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the process which involves many chemical reactions that plants use to produce all of the organic compounds they need
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What is the spectrum of light?
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a range of wavelengths from 400 to 700 nm of electromagnetic radiation
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What is the wavelength for violet-blue?
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400-525
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green-yellow?
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525-625
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orange-red?
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625-700
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What does the action spectrum show?
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Shows the percentage use of the wavelengths of light in photosynthesis (efficiency)
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What is light from the sun composed of?
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a range of wavelengths
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What is the main photosynthetic pigment?
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Chlorophyll
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Whats the difference in the absorption of red, blue and green light by chlorophyll?
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absorbs blue light the best, then red and least is green
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Why least in green range?
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most of the light is reflected since chlorophyll is green also
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Why is there still photosynthesis even when little green light is absorbed by chlorophylls?
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due to ACCESSORY pigments which absorb wavelengths that chlorophyll cannot
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What is an excited electron?
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an electron in the chlorophyll that is raised to a higher energy level when light is absorbed.
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What's a chlorophyll with an excited electron?
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a PHOTOACTIVATED chlorophyll
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What are photosystems?
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thylakoid membranes that are arranged in groups of hundreds of molecules including chloropyll
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What paths does the excited electron take in the photosystems?
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passed from molecule to molecule until they reach a special chlorophyll molecule at the reaction centre of the photosystem and this chlorophyll passes the excited electron to a chain of electron carriers
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What is non-cyclic photophosphorylation?
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The production of ATP using the energy from an excited electron from Photosystem II
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How does NADP get produced after the production of ATP?
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the electron that releases energy needed to make ATP is given away by photosystem II and accepted by photosystem I and replaces the one previously given away by photosystem I and thus PHOTO1 becomes photoactivated by absorbing light+give away another excited electron and is passed along a short chain of carriers to NADP+. NADP+ accepts 2 high energy electrons from the ETC and one H+ ion from the stroma to form NADPH.
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How is oxygen produced?
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By photolysis (the splitting of water molecules)
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What are photons?
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Light is made up of these.
They carry a set amount of energy, that is inversely proportional to the light’s wavelength. |
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Where does the light independent cycle occur?
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Stroma of the chloroplast
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First reaction of the calvin cycle includes?
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5-carbon sugar, RuBP (ribulose biphosphate)
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What is an essential substrate in the Calvin cycle?
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carbon dioxide
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Summary of reactions of Calvin cycle
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Where CO2 is converted to glucose using energy from ATP and NADPH as a reducing agent.
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Starting and end products of calvin cycle
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start: RuBP
end: G3P |
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phases of calvin cycle
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Phase 1: Carbon Fixation
Phase 2: Reduction Phase 3: Regeneration of RuBP |
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In carbon fixation what enzyme is used to catalyze the carboxylation reaction?
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Rubisco (abundant in stroma)
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What is formed as a result of the carboxylation reaction?
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TWO 3-phosphoglycerate
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What happens once the glycerate 3-phosphate is formed?
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1 ATP is converted into ADP, phosphate group attaches and becomes ONE 3-bisphosphoglycerate
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How is G3P produced?
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Reduction!
NADPH is oxidized to NADP+, the electrons are transferred to the carboxyl group of one 3-bisphosphoglycerate. |
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How is RuBP regenerated?
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By combining 5 G3P molecules and 3 ATP molecules to regenerate 3 RuBP molecules.
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For each G3P molecule, how many turns in Calvin cycle?
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3
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What happens in EACH turn of the Calvin cycle?
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1 CO2 molecule is used
3 ATPs are converted to ADP for energy 2 NADPH are oxidized to NADP+ and inorganic phosphate. |
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What are the G3P used for?
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converted to glucose, and then to starch for storage in the plant.
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How is G3P converted into glucose?
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Through a reduction reaction
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Where does the hydrogen and energy needed for this reaction come from?
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Hydrogen from NADPH and energy from ATP
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How is starch formed from the glucose?
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the condensation of many glucose phosphate molecules in the stroma.
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How can the rate of photosynthesis be measured?
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directly by the production of oxygen or the uptake of carbon dioxide or indirectly by an increase in biomass
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What is a PIGMENT?
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a molecule that ABSORBS a particular wavelength of light
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What colors do chlorophylls absorb?
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RED & BLUE
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What colors do carotenoids absorb?
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BLUE & GREEN
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What colors do phycobillins absorb?
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YELLOW & RED
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Why do pigments appear to be colored?
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Because they absorb particular wavelengths of light and reflect all other wavelengths
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