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What is the absorption spectrum of chlorophyll?
Chlorophyll a and b have two peaks of absorption between 400 NM to 480 nm (the blue end) and 550 to 700 nm (red end), neither cholorphyll absorb light in the middle of the spectrum which is about the green area.  
What is an action spectrum? What is the relationship between the action spectrum for photosynthesis and the absorption spectrum of chlorophyll? 
An action spectrum is the rate of a physiological activity plotted against wavelength of light. It shows which wavelength of light is most effectively used in a specific chemical reaction. Some reactants are able to use specific wavelengths of light more effectively to complete their reactions. For example, chlorophyll is much more efficient at using the red and blue spectrums of light to carry out photosynthesis. Therefore, the action spectrum graph would show spikes above the wavelengths representing the colors red and blue.

Photosynthesis in oxygen-evolving organisms is said to involve two distinct photosystems. Describe the two photosystems and provide two lines of experimental evidence that led to their discovery. 
Photosystem 1 (P700) and  photosystem II(P680) , the two work in a series connected by an electron transport chain. Primary charge-seperation events in the PSI reaction center cause the reaction center chlorophyll a molecule to donate electrons to NADP+ via an electron transport chain, thus making NADPH recquired by the Calvin cycle. The oxidized chlorophyll a molecule in PSI reaction center is then re-reduced by electrons generated by events in PSII and transferred to PSI by an ETC.   The energy generated by the ETC drives the transfer of protons from the stroma into the thylakoid lumen building up an electrochemical gradient. Protons move back down the gradient via the ATP synthase complex in the membrane è drives synthesis of the ATP recquired for Calvin cycle.  (When photosystem II absorbs light, electrons in the reaction-center chlorophyll are excited to a higher energy level and are trapped by the primary electron acceptors. To replenish the deficit of electrons, electrons are extracted from water by a cluster of four Manganese ions in photosystem II and supplied to the chlorophyll via a redox-active tyrosine. Photoexcited electrons travel through the cytochrome b6f complex to photosystem I via an electron transport chain set in the thylakoid membrane. This energy fall is harnessed, (the whole process termed chemiosmosis), to transport hydrogen (H+) through the membrane, to the lumen, to provide a proton-motive force to generate ATP. The protons are transported by the plastoquinone. If electrons only pass through once, the process is termed noncyclic photophosphorylation. When the electron reaches photosystem I, it fills the electron deficit of the reaction-center chlorophyll of photosystem I. The deficit is due to photo-excitation of electrons that are again trapped in an electron acceptor molecule, this time that of photosystem I. ATP is generated when the ATP synthetase transports the protons present in the lumen to the stroma, through the membrane. The electrons may either continue to go through cyclic electron transport around PS I or pass, via ferredoxin, to the enzyme NADP+ reductase. Electrons and hydrogen ions are added to NADP+ to form NADPH. This reducing agent is transported to the Calvin cycle to react with glycerate 3-phosphate, along with ATP to form glyceraldehyde 3-phosphate, the basic building-block from which plants can make a variety of substances.)
What is the role of electron transport in oxygen-evolving photosynthesis? Name the final electron donor and final electron acceptor in photosynthesis. Describe the path traveled by an electron in the electron transport process. 
The role of the electron transport is to move the chemical energy form that was converted into physical energy by moving one electron from one specific chlorophyll molecule to an acceptor molecule. The electron carriers make up the electron transport chain that transfer electrons to NADP+ reducing it to NADPH. This in turn allows the transport of protons across the thylakoid membrane from the stroma to the lumen, the flux of protons back across the membrane dries the activity of ATP synthases == ADP to ATP! The final electron donor is P700 reaction center and the acceptor is ferredoxin è NADP+ to NADPH   Light hits PSII and an electron from H2O is transferred to P680 as another electron is bound to plastoquinone through cytochrome b6f and then to plastocyanin via electron transfer components. Which is then released to P700 of PSI and released 
What is the role of electron transport in oxygen-evolving photosynthesis? Name the final electron donor and final electron acceptor in photosynthesis. Describe the path traveled by an electron in the electron transport process. 
The primary electron acceptor for the light-energized electrons leaving photosystem II is plastoquinone
Describe the process of ATP synthesis at the thylakoid membrane. Name the reactants, the energy source and the role of light in the process. 
Electron transfer processes in the membrane result in a net movement of proton from one side of the membrane to the other generating both a chemical gradient and electrical potential across membrane è proton motor force. Energy released by PMF down the electrochemical gradient through a chemical in a membrane – spanning ATP complex is used to drive the synthesis of ATP.   Release of protons produce a large gradient of protons and electrical potential   ATP synthase complex è located in stromal thylakoid membrane. Protons pass through CF. Is loose state coupled to the synthesis of ATP. A site binds to substrate. Conversion to tight state è synthesis of ATP. And then open state releases it   ATP synt. Is regulated heavily by light è inactive in dark and low pH levels è bad because potentially reversible 
Can ATP synthesis take place in thylakoid membranes kept in the dark? Is there any way we can manipulate the thylakoid membranes so that they may produce ATP in the dark? Explain.
If there is no light, the electrons cannot be excited and move down the ETC to have a transfer of protons across the thylakoid membrane from stroma (pH 8) to lumen (pH 4) create a proton gradient to allow the movement of ATP synthesis. 
Describe the three different sets of reactions in the Calvin cycle.
-Carboxylation of a five-carbon compound (CO2 acceptor) to give two molecules of a 3 carbon compound   -reduction of the 3 carbon compound to give a triose phosphate   -regeneration of five carbon acceptor from trios phosphate 
How many carbon dioxide molecules are required to generate a triose-phosphate through the Calvin cycle?
3 molecules of CO2 è one molecule of trios phosphate 
How is the enzyme Rubisco regulated by light?
Linked to light-driven reactions involves Rubisco-activase è activated by the reduction state of PSI è the pH level of stromoa is pH 7 and in the daytime its 8. Higher pH and MG2+ [concentration] è increases the activation state of rubisco 
What are the disadvantages of Rubisco? In what environmental conditions is the oxygenase activity of this enzyme problematic? Why do we think the oxygenase activity of Rubisco was not originally a problem? 
Problematic when CO2 levels become low and cells start using oxygenation instead of carboxylation in the Calvin cycle. It is bad because makes 2-phosphoglycerate instead of 3 phosphoglycerate. Which means it has to be converted to a 3 phosphoglycerate and sent back to the calvin cycle.  It takes complex reactions that consume ATP, involves ten enzymes in 3 subcellular levels and loss of 1 CO2 molecule.    Photorespiration = CO2 loss è all cellular metabolisms lower   It was believed that to have CO2 assimilation generated selected pressures for mechanisms that either recovered the carbon or prevented to oxygenate.  
Photorespiration is generally considered to be a wasteful process that decreases the yield of C3 plants. How could photorespiration be minimized in these plants?
If you pump more CO2 in, photo respiration will decease 
How is some of the carbon recycled from photorespiration? What are the three cellular compartments involved? Is ATP consumed in photorespiration? 
It is taken from the chloroplasts as a 2 carbon 2-phosphoglycerate to the mitochondria where it takes it to the peroxisomes, saves 3 out of 4  carbons to release CO2 and retake 3 phosphogylcerate.   Approx 2 ATP are consumed per each CO2 molecule released  
What units are used to measure light intensity?
In photons M-2 S-1
What is photosynthetic saturation? 
Also known as photoinhibition, this is caused by the absorption of too much light energy. It primarily affects photosystem II (chlorophyll a), though the exact mode of action is unknown. The damage is generally reversible, but long-term exposure to excessive light may generate damaging oxygen radicals, and result in degradation of the reaction complex.
What causes photosynthetic saturation at a certain light intensity?
The relationship between light intensity and photosynthetic rate is that if the intensity of the light is high then the rate of photosynthesis will increase. However the rate of photosynthesis will only increase to an extent after intensity of light reaches a certain point photosynthesis rate will stay still. Chlorophyll absorption also has something to do with it
What is the rate of dark respiration?
6 CO2 + 6 H2O (ATP & NADPH2 from Light Reactions) = C6H12O6 + 6 O2 Note: The oxygen liberated during the light reactions of photosynthesis comes from water.   The more ATP and NADPH is made during light reactions è the faster dark respiration will occur
What is the light compensation point? Is photosynthesis taking place at the light compensation point?
Minimum amount of light required for net photosynthesis to take place = range of 1-20 mmol of photons  
Which type of plant achieves photosynthetic saturation at lower light intensity, a C3 or a C4 plant? Which type of plant has a higher maximum photosynthetic rate, a C3 or a C4 plant?
A C3 plant achieves photosynthetic saturation at lower light; C4 has a higher maximum photosynthetic rate. 
How does the quality of light affect photosynthetic rate? Order from better to worse in terms of their ability to stimulate photosynthesis: green, white, red and blue light. Explain why that is the order.
Blue light has a maximal rate of absorbance, red has a second absorbance where green has very few and white has none.   The better quality (depending on nm and pigments in plants will induce absorption for chemical energy è green because wavelength is reflected and pass through affecting the pigments. 
Which plants have higher maximum photosynthetic rate, those adapted to live in the sun or in the shade?  Which plants achieve photosynthetic saturation at lower light intensities, those adapted to live in the sun or in the shade?
Plants adapted to growth in low light conditions often have low light compensation points   Plants adapted to full sunlight have higher light compensations 
Which plants show higher light compensation points, those adapted to bright sun or adapted to shade? Which plants have higher dark respiration rates?
Plants adapted to full sunlight have higher light compensations   Those whom have higher light compensation points 
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