Cyclic/NonCyclic Photophosohyrylation

[utdent20]

After reading Schuams.. I am totally confused.. PS1 Cyclic or Non Cyclic and waht about PS2 is that Cyclic?? anyone who knows the answer and can explain...would be of great help

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[keliao]

i was going over Schuams biol...it got me confused as well.
wikipedia explains it all

 

[laurielou]

Bacterial photosynthesis uses cyclic photophosphorylation and only ONE photosystem (electron is passed back to the reaction center -- hence why it is cyclic).

Plants & cyanobacteria use noncyclic photophosphorylation. They use two photosystems. The electron is not returned to the reaction center in PSII so that is why it is noncyclic. Instead, a new electron is formed from the splitting of water and the cycle continues on with this electron in PSII.

Edited to add... Sometimes when there is an accumulation of NADPH, cyclic photophosphorylation will be used rather than noncyclic to produce ATP. So plants can use BOTH noncyclic and cyclic.

 

[Pandawanda]

After reading Schuams.. I am totally confused.. PS1 Cyclic or Non Cyclic and waht about PS2 is that Cyclic?? anyone who knows the answer and can explain...would be of great help

it's hard for anyone to explain cuz they're long explanations but VERY simple..

i agree that scaum's is SOO confusing! lol..i used Kaplan which helped, but AP cliffs helped after i researched it on wikipedia.. so stay away from schuam's.. cliffs all the way =) or any other source.

 

[Svart Aske]

The photosynthesis section in Cliff's is excellent. Schaum's, though detailed, is very convoluted and boring; there's little point going through that book if you can't retain most of the information.

 

[marscole]

in non-cyclic - production of NADPH and ATP which are needed for calvin cycle
in cyclic - ATP is running out... so... need to enter this cycle to reach equilibrium...
plant and bacteria use different wavelength in PS1 and PS2. however, both undergo similar concept in NADPH and ATP productions.

 

[pbure9]

The photosynthesis section in Cliff's is excellent. Schaum's, though detailed, is very convoluted and boring; there's little point going through that book if you can't retain most of the information.

agreed its good stuff.

 

[myair]

in short :

PS1 Cyclic

or Non Cyclic PS2 and PS1

 

[doc3232]

Cliffs does a very nice job. I think Kaplan also did.
Barrons wasn't very detailed, which made me uncomfortable, but that might be what is needed for the DAT.

 

[Isradoc1983]

hmm I didn't look at photosynthesis in bacteria, but in plants
PS1 can be both cyclic( atp produced) and non cyclic (nadph produced)
if its non cyclic it'll be left with e- holes ( in PS1 after producing nadph) these holes will be filled by PS2 in a non cyclic i.e now PS2 will have e- holes. now PS2 is a strong oxidizing agent and will split water to fill its e-.
on a side note the H+ from water will be used to form NADPH

hope it helps

 

[utdent20]

this became a good thread.. thanks guys..