Photosynth (don't forget to study diagrams)

Question 1

What are all four lineages of photosynthetic organisms?

Answer 1

Cyanobacteria, green algae, eukaryotic algae, plants

Question 2

What is the great oxygenation event?

Answer 2

When oxygen-fixing, photosynthetic bacteria started to fix oxygen into the atmosphere

Question 3

Where is photosystem I found, where is photosystem II found ?

Answer 3

PS I: stoma thylakoid membranes
PS II: mostly inner grana space, some stroma thlakoid membrane

Question 4

What are the the six protein involved photosynthesis in order?

Answer 4

PSII, plastoquinone (PQ), cytochrome b/f6, plastocyanin PC, and ferredoxin Fd, PS I

Question 5

What does light absorbtion do to the PS complexes?

Answer 5

It makes the redox potential more negative

Question 6

What is the ultimate electron donor? how about acceptor?

Answer 6

Donor: H2O
acceptor: NADP+

Question 7

What is more energetic: blue or red light?

Answer 7

Blue light

Question 8

What type of light can the PS rxn center absorb? (red or blue)? What about carotenoids?

Answer 8

PS: Red light (low energy so wont damage components)
carotenoids: high energy blue light

Question 9

How many oxidation states does the mangesium core have? What does it decays to in the dark?

Answer 9

Five states. Decays to state 1.

Question 10

What is the quantum yeild of O2 (photons needed per an O2 released)? How about Chl needed? How about electrons?

Answer 10

four electrons
2400 chlorophylls
9 -> 10 hv (photons)

Question 11

What is the average size of the antenna for the PS’s ?

Answer 11

300 chl per a photosystem

Question 12

how many photons does it take to fix one carbon?

Answer 12

9 to 10 photons

Question 13

What is required from the light rxn to run the CBC/dark rxn cycle?

Answer 13

2NADPH and 3 ATP

Question 14

How many photons per a 2 NADPH and 3 ATP?

Answer 14

9 or 10 photons (8 for linear + 1 for cyclic)

Question 15

What is the electron to ATP ratio in photosynthesis

Answer 15

2:1 e-: ATP

Question 16

what electron carrier does cyclic electron transport?

Answer 16

Ferridoxin (Fd)

Question 17

Which PS is in the stromal membranes? Which PS is in the grana stacks? Where does ATPase and Cytob6f lie?

Answer 17

PS II: thylakoid
PSI: stromal
ATPase: stromal
cytob6f : everywhere

Question 18

How many mV across the membrane is needed to make ATP? Where do these energies come from (pH or delta psi) in the thylakoid, mitocondria, and bacterial membranes

Answer 18

180 mV
Thylakoids like high pH difference and low psi
mitochondria like lo delta pH and high delta psi
bacteria go either or

Question 19

What are the exact units for an Einstein and what does it measure?

Answer 19

Units are kJ/mol of photons. Used to measure light

Question 20

What is the chemiosmotic hypothesis?

Answer 20

the protonmotive force forces is made up of both pH and psi

Question 21

What are the 5 ways plants/algae can concentrate CO2

Answer 21

Carboxysomes, pyrenoids, C2, C4, and CAM

Question 22

What are the major nutrients of life?

Answer 22

C, H, N, O, P, S

Question 23

What is fluorescence’s relation to photochemistry

Answer 23

it is 1-photochemistry. When there is a charged molecule, it can either use the charge to do photochemistry or dissipate the energy as fluorescence

Question 24

Why is there two photosystems instead of just one?

Answer 24

Stops electrons from backsliding in the wrong direction or from releasing their energy as heat/light

Question 25

what does one Einstein equal?

Answer 25

Kj/mol of photons

Question 26

The photosystems go from a uncharged state with a ___ redox potential, to an charged state with a ___ redox potential

Answer 26

uncharged = possitive
charged = negative

Question 27

how many chlorophyll molecules per a rxn center on avg?

Answer 27

around 300 Chl

Question 28

Organize the molecules from high energy absorbing to low energy absorbing: carotenoids, P680, Chl a, Chl b

Answer 28

Carotenoids, Chl b, Chl a, P680

Question 29

What is the equation for the protonmotive force?

Answer 29

pmf = (delta mu/F) =60 (delta pH) + delta psi [mV]

Question 30

How efficient is photosynethsis?

Answer 30

31% energy conversion

Question 31

What is Mitchell’s Chemiosmotic Coupling hypothesis?

Answer 31

The energy used to make ATP across membranes is stored an electro-chemical graident

Question 32

What is the photosynthetic equation (fixation of one carbon from the air)?

Answer 32

CO2 + 2H2O +n(hv) –> CH2O +H2O +O2

Question 33

What is the difference between the F0 subunit and the F1 subunit.

Answer 33

F0: proton channel with multiple subunits. This is the embedded part of the protein
F1:ATPase with 9 total subunits