Photosynthesis
Introduction
Introduction
1) What is Photosynthesis basically? (name the raw materials and products formed and which one is by-product)
2) What are the energy changes occurring here?
3) Nature of the reaction
( anabolic, endergonic and oxido-reduction process) ⭐
4) Simple equation to represent photosynthesis
5) Importance of Photosynthesis (2)
6) Fact about the dry matter produced by land and aquatic plants
Early Experiments
Verification Experiments
1) To prove light and chlorophyll is necessary for photosynthesis.
i) What colours do starch test produce?
2) To prove CO2 is necessary for Photosynthesis
i) What is the name of the experiment
ii) What is the chemical used in this expt.
Joseph Priestley's Experiment
1) What did this experiment prove?
2) Explain how he did this experiment?
3) What were the conclusions that he made?
Jan Ingenhousz's Experiment (I forget this a lot)
1) What did this experiment prove?
2) Explain how he did this experiment?
3) Which plant did he use?
Julius Von Sachs' Experiment: (Remembering trick: Sachs - chloroplast sac)
1) What did this experiment prove?
2) What did he call the spherical bodies?
3) In which form is food stored in plants?
T.W Engelmann's Experiment: ⭐
1) What did this experiment help with?
2) Which organism did he experiment on?
3) What kind of bacteria did he use? (aerobic or anaerobic) and name.
4) What was the function of these bacteria?
5) How did he do this experiment?
6) What were his observations?
7) What were his conclusions?
Cornelius van Neil's experiment:
1) What did he tell in this hypothesis?
2) Which microorganism did he use in this experiment? (I forget this a lot)
3) Where is hydrogen released from?
4) How was this hypothesis proven?
Where does Photosynthesis take place?
i) Where does photosynthesis take place in green plants? (2)
ii) Which is the most photosynthetically active part of the plant? Why?
iii) What is PAR? What is it's range? What is normal light range?
Chloroplasts
i) What is a chloroplast?
ii) In which organisms are it present in? (Eukary/ Prokary or both?)
iii) Comment on the membrane system present in chloroplast. (3 membranes actually....well sorta)
iv) Terms to note:
a) Thylakoid
b) Grana/Granum
c) Stroma
d) Stroma Lamellae
v) Where do Light and Dark reactions take place? (why are they called so?)
vi) What kind of DNA and ribosomes are present in chloroplasts?
Photosynthetic Pigments
1) What is a pigment?
2) What are the 4 types of pigments and what are their respective colours?
3) Structure of Chlorophyll Pigments:
i) What are the 2 components of a pigment?
a) Porphyrin head:
i) What is the structure of this part?
ii) What are other molecules that have a similar structure?
iii) What process takes place here?
iv) What kind of metal ion is present here?
b) Phytol tail:
i) What is this chain made up of?
ii) What is the main function of this?
4) What are the accessory pigments(what is it also called?) and primary pigments?
ii) Give their functions (2 for A.P and 1 for P.P)
Absorption Spectrum
1) What does this graph show? Try and draw it.
Action Spectrum
1) What does this graph show? (Pg 94).Try and draw it.
Draw the correlation graph between them
Ruben, Kamal et al. Experiment
1) What kind of oxygen did they use?
Light Reaction
Introduction
1) Why is this called the light reaction?
2) What phase of photosynthesis is this?
3) What is this phase responsible for the formation of? (Its not starch and all)
4) What different phenomena are included here?
Electron Transport System
1) This is basically the downhill movement of an excited electron. But what is the main purpose of this?
2) Which molecule will be able to be produced by this mechanism?
Photosynthetic Units/ Pigments
1) What are these systems made of (components)?
2) What is their main function?
3) What is a reaction centre? Which pigment is it made up of?
4) Types of reaction centers (2). What wavelengths do they absorb?
5) What are LHP's? What are they also called?
6) What is the function of an LHP?
7) How is an LHC different from an LHP? What is the advantage of an LHC?
8) Differences between PS I and PS II:
i) Where are they present? (w.r.t to thylakoid membrane and generally in chloroplast?
ii) Which one is associated with the splitting of water?
iii) Which photophosphorylation do they participate in?
9) What is my hypothesis on why PS I is more common? ⭐
Miscellaneous
1) Between NADPH and ATP, which ones are related to ETS and Photophosphorylation?
Types of Photophosphorylation
Cyclic Photophosphorylation
1) 1) What photosystems come into play here?
2) Where does this occur? ⭐
3) What is lacking in the stroma lamellae? (2)
4) Does H20 splitting take place here? Why not? (it is closely related to the "cyclic" abbreviation)
Non-cyclic Photophosphorylation
1) What photosystems come into play here? How are they connected?
2)Which one is excited first?
3)What is type of Photophosphorylation also called? Why is it called so?
4) Where does this occur? ⭐
5) Are both NADPH and ATP produced by this?
6) Process:
i) Draw a diagram of how this works
ii) What is the important point to note about the energy of the electron as it passes downhill?
P.S if you know how this gradient helps in ATP synthesis (especially the H carrier) then you're a genius)
iii) Does the electron return to PS II? Why not? (Remember Chaitra Mam's Loyalty analogy)
7) Splitting of Water:
i) What is the purpose of this thing?
ii) Where does this reaction take place?(it is closely related to the location of PS II
iii) Write the equation for it.
iv) What is the catalyst and promoter here?
8) NADPH Formation:
i) At what stage is this formed?
ii) What is the enzyme involved here?
iii) Write the Equation.
Difference between Cyclic and Non-Cyclic Photophosphorylation
1) PS's involved
2) Whether external electron source required.
3) If it is connected to the evolution of oxygen.
4) What chemical intermediates it synthesizes
5) Light intensity, oxygen presence, CO2 conc. needed for optimum reaction.
6) Which type is connected with photosynthesis in bacteria and plants.
Chemiosmotic Hypothesis
1) Who explained it?
2) What does this mechanism explain?
3) What does the Chemiosmosis process require? (4)
4) Why is it called chemiosmosis?
5) What process is linked with ATP Synthesis?
6) For the proton gradient to occur, where should the H+ conc. be more and less?
5) Processes that lead to formation of proton gradient (3):
TRY FIGURING ALL 3 BEFORE LOOKING
b) Photolysis of water:
i) How does this help proton gradient?(check the photolysis equation)
ii) Where is the H+ released? (again, closely related to location of PS II)
c) Electron Transport system: (The genius part I was talking about)
i) How does that downhill gradient thing actually help?
ii) Which electron acceptor is main here?
iii) How does it change H+ conc. between stroma and lumen?
iv) What did Chaitra Mam say about the electron acceptor nature.
a) NADPH Formation:
i) How does NADPH contribute? (it is closely related to the location of NADP enzyme)
ii) How many H+ does it remove?
Formation of ATP:
1) How is the gradient broken down (the type of diffusion)? What is the importance of this breakdown?
2) Where is the energy for ATP synthesis derived from? (closely related to the 1Q.
2) Which enzyme is responsible for ATP synthesis?
3) Name the 2 components of this enzyme.
4) What role does each play?
5) What happens to the CF1 part during synthesis?
6) True or False. NADPH and ATP are required for synthesis of food materials.
Dark Reaction
Introduction
1) Why is it called the dark reaction? Does it actually occur in the dark (i.e is it light driven)?
2) Which phase of photosynthesis is this?
3) Where does it occur? ⭐
4) What is it "directly" dependent on and what is it not dependent on? How can we verify this fact? (key phrase: continues for some time)
5) Which cycle occurs in dark reaction in ALL plants?
6) What is the cycle that can support the above cycle in certain plants. (Give the other name for it)
7) Why were these cycles named as C cycles?
8) What form of carbon did Melvin Calvin use for his experiments?
9) Which organism did he experiment on?
Types of Cycles
C3 Cycle
1) V.I.P statement about this cycle's occurrence ⭐
Process
2) What is the primary acceptor of CO2? How many carbon atoms does it have?
3) What acceptor did scientists initially think it was?
4)
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