Lecture 12: photosynthesis Flashcards
Write the overall equation of photosynthesis
6CO2 + 6H2O –> C6H12O6 +6O2
Where does the O2 come from
H2O not CO2
What are the 2 stages of photosynthsis called
- light dependent
- calvin cycle
Where are the light dependent reactions occur?
thylakoid membrane
Where does the calvin cycle occur?
stroma
Why do we see green in plants?
All other colors are absorbed by chlorophyll and green is reflected back
What is a characteristic of chlorophyll?
Amphipathic
What is the first step of photosystems?
catch energy from light(e-)
Where does the chlorophyll catch light?
antenna chlorophyll
what is step 2?
water gives e- back to the chlorophyll for the one it lost
and O2 is produced
step 5?
goes to photosystem 1 for more energy
step3?
goes to pq (coenzyme)
step 4?
goes to cyt
step 6?
FD-NADP+ reductase
step 7?
NADP+ as final electron acceptor
Where does the proton(H+) movement flow?
Outside-> pq-> cyt->ATP synthase–ATP
How does paraquot harmful to plants
blocks NADP reductase from accepting electron
Where is the calvin cycle located
stroma
How many steps does the calvin cycle have?
15
What is carboxylation?
add CO2 to RuBP
What is reduction for calvin cycle?
energy from ATP and NADH lead to G3P
What is regeneration of RuBP
G3P are reorganized as combined to make RuBP
What happens to the e- in PS II?
enters into the photo electron transport chain
What happens to the e- in PS I?
e- reduces NADP+
Trace the steps of NADP and ATP production by photosynthesis
OK
What enzyme catalyzes carboxylation?
Rubisco
What are the inputs of carboxylation?
co2, rubp
What does rubisco do?
create an unstable intermediate after RuGP +CO2
What happens after the unstable intermediate by rubisco is formed?
breaks down into 2 3-PGA stable
At what pH is rubisco most active?
Around 8.8
What conditions is rubisco most active?
a little. less concentration of H+
Why does a small amount of G3P leave the chloroplast?
starch or glycolysis
Why is RuBP regenerated?
Needed again for carboxylation
