Photosynthesis Flashcards
Where do the light reactions occur?
Thylakoid membrane
Where do the dark reactions occur?
The stroma
Where are protons pumped out of and into to?
Pumped out of the stroma and into the thylakoid lumen
What is analogous to cytochrome c in the light reactions?
plastocyanin
What is analogous to Q in the light reactions?
plastoquinone
What is a byproduct of the light reactions?
oxygen (that we breathe!)
What molecule are electrons in the light rxns extracted from?
H20
What is at the center of the D1 and D2 catalytic subunits of PSII?
The special pair of chlorophylls (P680)
What surrounds the special pair?
The light harvesting complexes
What is a key element that chlorophylls contain?
Magnesium
Why are there so many pigment molecules?
Diff types of pigment absorb diff wavelengths, thus ensuring we absorb most energy of the sun
True or False - it takes about 10-100 picoseconds from the time an antenna pigment absorbs a photon to when the energy excites P680
True
How are the photons transferred from the antenna pigments to P680?
Resonance transfer
What primary electron acceptor is waiting to grab an electron from P680?
Pheophytin
When e- deficient, P680+ is biology’s strongest ____ ____.
oxidizing agent
What is one element found in the oxygen evolving complex?
There are 3: Manganese, Calcium, and Oxygen
P680+ is a strong ____, while P700* is a strong ____.
oxidant, reductant
True of False - in the cyclic pathway, Ferredoxin takes electrons back to Cytochrome b6f (when NADPH is abundant) where they can be used by Q cycling to produce ATP
True
True or False - The light reactions do not consist of an ATP synthase structure.
False
Ferredoxin works with __ to reduce NADP+ to NADPH
FNR
True of False. FNR accepts electrons one at a time from the FeS cluster in Ferredoxin to transfer to the NADP+ domain.
True
When NADP+ is low, what does the cell have plenty of?
NADPH
How many water molecules are needed to form O2?
2
What does P680 get its electrons from?
a nearby tyrosine in D1
