Photosynthesis Flashcards
plant (13 cards)
Where does photosynthesis occur?
In side the chloroplast of the plant with the photosystems and thylakoids
Why do plants want a wide variety of pigments?
Different pigments absorb different wavelengths of light so by having many different pigments you can maximise light absorption for photosynthesis
What are the three limiting factors of photosynthesis and how can they be overcame?
Light intensity - artificial light
CO2 conc - use of CO2 waste
Temp - Green houses at spec temps
What is photoionization?
This is when light is absorbed by PSII, it excites the the e- inside which leave the chlorophyll
What is photolysis?
This is where light splits water into Protons and oxygen which provides e- for the ones that were lost in photoionization
What happens in the Light - Dependent reaction - non cyclic photophosphorylation (4)
PSII phto, chain,pump,NADPH,synth
1) when PSII absorbs lights it undergoes photoionization releasing its e- (replaced via photolysis
2)These e- move down the electron transfer chain which provides E via oxidation reduction reactions to a protein complex which actively transports H+ into the thylakoid space to maintain H+ gradient
3) e- at the end of the chain do NADP + H+ = NADPH
4)Cuz of proton gradient H+ moves back to stroma through ATP synthase via chemiosmosis, this provides energy for ADP + Pi = TP
Where does the light dependent reaction occur?
between the stroma and thylakoid space
What is cyclic photophosphorylation in the light dependent reaction?
When PSI absorbs light 1 photoionization reaches the end of the e- transfer chain and is sent back to the start which provide E for H= to actively be pumped into the thylakoid space
Where does the light -independent reaction or Calvin cycle occur?
Inside of the stroma
What happens in the light -independent reaction or Calvin cycle? - dont forget catalysts
1)CO2 + Ribulose bisphosphate = 2 Glycerate 3 phosphate , catalysed by rubisco
2) Glycerate 3 phosphate is reduced by NADPH and ATP produced in the light dependent reaction into 2 Triosephosphate
3)80% of the triose phosphate is converted back to Ribulose bisphosphate whilst 20% goes to organic substances - Glucose,Amino acids,Lipids
What are some similarities between respiration and photosynthesis? (3)
Both utilise electron transfer chains
Both use ATP synthase and chemiosmosis to generate ATP
Both use proton gradients
What are some differences between respiration and photosynthesis? (3)
In the mitochondria and Chloroplast
Final e- acceptor Oxygen and NADP
Endothermic and Exothermic
