Photosynthesis Flashcards
Describe what happens during photoionisation in the light dependent reaction.
Chlorophyll absorbs light energy
Electrons are lost
Describe the light dependant reaction
1) Chlorophyll absorbs light energy and excites electrons
2) Electrons remove via photoionisation
3) Electrons move along the ETC, releasing energy
4) The energy released is used to from proton gradient
5) H+ ions diffuse through ATP synthase, providing energy to join ADP and Pi to form ATP (photophosphorylation)
6) Photolysis of water produces 2 protons, 2 electrons and 1/2 oxygen
7) NADP reduced by electrons
Two products of the LDR that are required in LIR
ATP and reduced NADP
Is proton pumping to form a proton gradient an example of active transport?
No, as AT requires ATP. Energy for PP is from high energy electrons.
Describe the light independent reaction
1) Carbon dioxide combines with RuBP
2) To produce two GP using (enzyme) Rubisco
3) GP is reduced to triose phosphate
4) Using reduced NADP
5) Using energy from ATP
6) Triose phosphate converted to glucose, amino acids, regenerated back into RuBP
Where is rubisco found in a cell?
Stroma
In the investigation of the rate of photosynthesis, why do scientists measure the rate of production of oxygen?
1) Oxygen is produced in the LDR
2) The faster oxygen is produced, the faster the LDR
Explain why plants that have more chlorophyll will grow faster than plants with less chlorophyll
1) Have faster production of ATP and reduced NADP;
2) So faster LIR
3) Produce more sugars that can be used in respiration;
4) So have more energy for growth;
5) Have faster synthesis of new organic materials
ATP is produced in the LDR, so why is this not plants only source of ATP?
1) Plants don’t photosynthesise in the dark
2) Not all the parts of the plants photosynthesise
3) Plants require more ATP than is produced in the LDR
4) ATP is used in active transport
Describe the effect of adding a herbicide to the ETC
1) Reduced proton gradient across thylakoid membrane;
2) So less ATP produced;
3) So less reduced NADP produced;
4) So LDR slows
When producing a chromatogram, explain why the origin is marked in pencil rather than ink
Ink and leaf pigment would mix
While making a chromatogram, describe the method used to separate the pigments after the solution of pigment had been applied to the origin
1) Level of solvent below origin/line
2) Remove before solvent reaches the top
What are the advantages of a plant having different colour pigments in leaves?
Absorb more wavelengths of light for photosynthesis
Explain the relationship between the stomata opening and photosynthesis
1) Stomata allows uptake for CO2
2) CO2 used in photosynthesis
What is the equation to calculate Rf value?
Distance pigment moved from origin / Distance solvent front moved from origin
1) Inner membrane
2) Thylakoid membrane
3) Stroma
4) Granum (stack of thylakoids)
5) Thylakoid space
6) Outer membrane
