photosynthesis

The process of using sunlight to produce carbs. It uses sunlight CO2, and water and makes O2 as a BYPRODUCt

6CO2 + 12H2O + light energy → C6H12O 6 + 6H2O + 6 O

Photosynth happens in the green pigment chlorophyll has thylakoids - disks stacked on top of each other to form grana Stroma is the fluid filled space between the thylakoids and within in the inner membrane.

light dependent reaction - make O2 from H2O Calvin cycle - independant of light, makes sugar from CO2

Chlorophyll molecules working together in groupd Where the reactions happen photosystem I, photoystem II proteins located in the thylakoid membrane in the chloroplasts part of the light dependant process in photosyth Produce enhancement effect

When the rate of photosynth more than double when are exposed to red and far red light

Feeds an ETC that powers other proteins that pump protons to ATP synthase It gets its electrons from photolysis, splitting up water

• photon hits chlorophyll, chloro is oxidized, high eng elect goes to pheophytin 2.pheophytin go through ETC into thylakoid memb • platiquinone takes elect from pheothytin to cytochrome complex inside thylakoid • electron in ETC participate in redox react • redox react pump protons across memb

pheophytin - similar to chlorophyll, but accepts electron not donates Plastoquinone (PQ) - happens after the pheophytin, brings elect to cytochrome complex

Excited electrons leave photosyst II and go down the transport chain photosyst becomes electroneg and strip electron from water also produces oxygen in process called oxygenic photosynth 2H2O → 4H+ +4e– +O Only known protein complex that can oxidize water in that way

diffuse down the electrochemical gradient protons flowing through ATP synth drives phosphorylation of ADP

Reduces NADP+ to NADPH 1. excited elect from photosys I goes to ferrodoxin 2. NADP+ reductase transfer proton and 2 electron from ferrodox to NADP+ , make NADH 3. NADPH is electron carrier to reduce other things

model of how photosyst II and I interact 1. elect is excited by photon in P680 in PS II, goes to pheophytin, decreases pot eng in ETC 2. PQ uses eng to transport protons across the thylakoid memb, into cyto comp 3. buildup of protons pushes ATP synth to make ATP 4. cyto comp passes elect to plastocyanin (PC) 5. PC bring elect accross memb to thylakoid PS I 6. new elect replaces elect from p700 7. elect from PS I enter ETC, to Ferrodoxing and reduce NADP+ to NADPH

Types of chlorophyll P680 is found in PS II P700 found in PS I

photosynth is best with 680 and 700 nm wavelength, Correlates to P700 and P680 chlorophyll molec in PS I and II

photosyst 2 is first but it was found second photosyst 1 was found first

takes place in the chloroplast stroma- C3 plants in Bundle Sheath - CAM, C4 plants 1. fixation- CO2 reacts with RuBP, is fixed to 3-phosphoglycerate molecs 2. reduction - the 3-phosphoglycerate is phosphorylated by ATP and reduced by NADPH to make 6 G3P, 1 G3P leaves 3. regeneration - remaining G3P is used to regen RuBP

3 cycles to make 1 G3P there are actually 6 made but the other 5 stay in the cycle

synthase found in first step of calvin cycle in carbon fixation very slow most abundant protein on earth leaves need a lot of it

it is very slow and evolved early, when O2 conct were low if there is no CO2 to bind with then it will bind with O2 and cause a loss of eng This can happen when it gets dry, stomata close to keep water in, but CO2 can’t get in

when rubisco binds with O2 instead of CO2 makes no organic fuel (no calvin cycle) no atp wastes energy makes H2O2 - bad baggage from earlier time when much more CO2 and ability didnt matter now its issue

stroma - found in chloroplast, like mitochondrial matrix stoma - part of leaf structure, in between guard cells, helps gas exchange Stomata - multiple of stoma

LIght reactions with O2 (in mesophyll cells) kept separate from Calvin cycle with CO2 (in bundle sheath, not present in c3 plants) Uses Pep Carboxylase uses a 4 carbon molec instead of G3P which is C3 happens in dry places corn

Crassulacean acid metabolism Works at night CO2 Is stored at night to be used in the day Day :Stomata closed, Conserve water, no CO2 uptake, Light reactions make ATP and NADPH and O2, Calvin cycle runs, Night: takes in CO2, does PEP carboxylase, stores CO2 in malic acids