What are the two requirements of chemiosmotic hypothesis? What molecule is responsible for creating the H+ gradient?

What molecule is responsible for creating the H+ gradient? Ubiquinone quinone quinol or catechol

What’s new in this book’s presentation of respiration? What’s confusing?

What’s new in this book’s presentation of respiration? What’s confusing? By Mariana Ruiz Villarreal LadyofHats - the diagram i made myself using adobe illustrator. as a source for the information i used the diagrams found here:[1], [2], [3], [4], [5], [6] and [7]., Public Domain, https://commons.wikimedia.org/w/index.php?curid=8152599

How many proteins are involved? What are their roles? Q + 2e- + 2H+  QH2 Q + 2e- + 2H+  QH2 Which metalloproteins have their own names?

What is the reaction that provides the energy for ATP formation? How many and which metals are involved in respiration? In what types of centers are these metals in?

Complex III – also creates H+ gradient while moving along e- H+‘s are pulled from inside for Q redn matrix Q QH2 2 Q H+ ‘s are released outside from QH2 oxidn 2 x QH2 cytosol c1 c Cyt c

Complex IV – Cytochrome C Oxidase Fe(II)  Fe(III) Cu(II)—Cu(I)  Cu(I)—Cu(I) Cu(II)  Cu(I)

Complex IV – Cytochrome C Oxidase oxy O-O2- H+ limiting Internal redox peroxy reduced – H2O ferryl – H2O H+ limiting oxidized START

How do chl molecules behave as attennae? Photosystem I SUN CATCHER Each lobe of clover-leaf-shaped crystal of photosystem I contains 12 different proteins, shown here in different colors with only the protein backbone of each depicted. Amid the proteins are 96 chlorophylls (pale yellow) as well as other cofactors.

What are the two processes in PS and what are their names? carboxylation regeneration reduction Outside thylakoid: 4 H+ lost from here Inside thylakoid: 4 H+ produced here What is the OEC?

H2O  PSII plastoQ  cyt b6f  plastocyanin  PSI  Fe2S2  NADP+ carboxylation regeneration reduction Outside thylakoid: 4 H+ lost from here Inside thylakoid: 4 H+ accumulates here Net ET reaction: H2O  PSII plastoQ  cyt b6f  plastocyanin  PSI  Fe2S2  NADP+

The magical partnership of Metal and organic redox Ubiquinone Stigmatellin - co-crystallized in Cyt B1C

“Z-Scheme” How is the energy of light converted into chemical energy in the 1st step? How many and which metals are involved in PS?

Eox (V) +1.2 V +0.6 V 0.0 -0.6 V -1.2 V + 4e- PSI parallels Complex IV= cyt c oxidase in respiration Plastocyanin in PSI parallels cyt c in respiration + 4e- Mn4O4 cluster in PSII parallels Complex I in respiration

confusing?

What are the similarities and differences between respiration and photosynthesis?

Cristae and thylakoid: inner membrane structures Cyt bc in mitochondria ~ cyt b6f in chloroplasts Small organic electron/proton carriers Multi-metal site for multi electron processes Reactive centers embedded in membranes Creation of proton gradient PSII reduces a Q to QH2; PSI is like complex IV Plastocyanin functions like Cyt c Use of aa residue as radical (Tyr)

PSII @ 3.5 Å resolution

Cytochorme b6f (analog of respiratory cytochrome b1c)

PSI Reaction Center cofactors only

PSI Reaction Center E- acceptor Chl pigments