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Photosynthesis, Abnormal conditions - Coggle Diagram
Photosynthesis
energy within the light is captured to synthase carbohydrates
6CO2+12H2O+Light energy------>C6H12O6+6O2+6H20
Steps:
Stage1:Light dependent reaction
Noncyclic
4-ATP synthase:
3-ATP synthesis:The photophosphorylation drived by flow of H+ from the thylakoid lumen into stroma (against gradient)
1-PSII:
Reaction center
1)P680-->P680*(exited) and it is unsable so it trasfered to primeary e- acceptor(Pc) and captured
2)H2O oxidized to replace e- in P680* and O2 prodused
Antenna complex
Absorbs photons & transfer energy by resonance energy transfer
2-PSI:
boosts the e- from Pc by light input and goes to Fd
3-NADP+ reductase:
2 e- from Fd +(H+)+NADP+=NADPH to remove H+ from stroma
NORMAL
amount of (ATP+NADPH)
Cyclic
NADP+ or ATP is low
Photosystem 1:e- from Pc + light input-->goes to ferredoxin(Fd) then QB then Pc and then PSI to produce H+ electrochemical gradient used to make ATP by ATP synthase and e- return to PSI
NOTE:ATP only produced
Normal condition
Stage2:Dark reaction/Calvin cycle
1-Carbon fixation
6CO2 +rubisco(enzyme)+RuBP=12(3PG)
2-Reduction and Carbohydrate production
12(3PG)+12ATP=12(1,3-BPG)
12NADH+12(1,3-BPG)=12G3P+12NADP+
10 G3P is used for RuBP regeneration +2G3P converted to Glucose and other sugars
3-RuBP regeneration
10G3P +6ATP=6RuBP
Mostly occur in mesophyll and CO2 enter through stomata(pores in leaves)
Abnormal conditions
C3 plants
1-as BuBP will work as oxygenase and produce CO2
2-do photorespiration to produce CO2 needed
But it will limits the plant growth
like:cool environments/more O2 than CO2
like:wheat plants/Oak leaves
NOTE:no ATP is used
C4 plants
use barriers to stop photorespiration
physicals
Hatch-Stack pathway (two-cell layer)
1-Mesophyll cells
exposed to high O2 low CO2
1-CO2(from stomata)+4PEP (by PEP carboxylase)=Oxaloacetate
2-isolated to prevent RuBP from exposing to O2
3-Oxaloacetate enter as Malate and become Pyruvate+CO2 (NOTE:Pyruvate is regenerated by adding ATP and Pi to it)
1 more item...
2-Bundle-sheath cells
like:corn and sugarcane
Time
CAM
CLOSE their stomata during the day/OPEN them at night (preserve water)
NIGHT:CO2 enter and converted to malate and it converted to Oxaloacetate
DAY:Malate leaves central vacuole and broken to CO2 +Calvin cycle start
like:cacti and pineapple
for:warm dry climates
NOTE:ATP is used
Bad environmental conditions