2.1.2 Photosynthetic Electron Transport Flashcards
What are the two dimers of Chlorophyll A that can accept electrons
P700 and P680
What do plastiquinone, cytochrome, plastocyanin, and ferredoxin have in common
They are all proteins that act as redox factors capable of accepting/donating electrons
Why are two light reactions necessary?
In order to get enough energy to split water
What are the two sites of getting H+
Water splitting and PQ
Of cyclic electron flow and noncyclic electron flow, which one is normal in plants?
non cyclic
What is PQ able to do?
Move H+ inside the thylakoid
what is the role of rubisco
CO2 capturing enzyme
What is the product of rubisco and CO2
2 PGA molecules
What energy is needed for each CO2 reduction? (C3)
3 ATP and 2 NADPH
What makes phtorespiration undesirable?
O2 is placed in active site of rubisco instead of CO2. O2 is consumed, CO2 is released, and no energy is conserved.
What can inhibit photorespiration
High concentrations of CO2
What can increase the rate of Photorespiration
High temp
What makes C4 different from C3
PEP carboxylase has higher affinity for CO2 (compared to rubiscoe). Therefore, the stomata dont have to be open as much to get CO2. reduced water loss
What causes decreased photorespiration in C4 plants
decarboxylation that increases CO2 conc.
what are the best conditions for C3
low light, high humidity, lower temp.
