Difference between revisions of "Q-junction"

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high-resolution terminology - matching measurements at high-resolution

Q-junction

Description

The Q-junction is a junction for convergent electron flow in the electron transfer system (ET-pathway) from type N substrates and mt-matix dehydrogenases through Complex I (CI), from type F substrates and FA oxidation through electron-transferring flavoprotein complex (CETF), from succinate (S) through Complex II (CII), from glycoreophosphate (Gp) through glycerophosphate dehydrogenase complex (CGpDH), from choline through choline dehydrogenase, from dihydro-orotate through dihydro-orotate dehydrogenase, and other enzyme complexes into the Q-cycle (ubiquinol/ubiquinone), and further downstream to Complex III (CIII) and CIV. The concept of the Q-junction, with the N-junction and F-junction upstream, provides the rationale for defining pathway control states and categories of SUIT protocols.

Reference: Gnaiger 2009 Int J Biochem Cell Biol, Gnaiger 2014 MitoPathways

MitoPedia concepts: MiP concept, SUIT concept

MitoPedia methods: Respirometry

MitoPedia topics: Enzyme

Contributed by Gnaiger E 2010-08-15; edited 2016-02-12, 2016-03-28.

Convergent NS-linked electron flow at the Q-junction, exerting an additive effect on flux, versus electron gaiting for separation of single N- and S-input pathways (upper panel: Gnaiger 2009; lower panel: Hatefi 1962 J Biol Chem-XLII). Modified Fig. 1.5 in Gnaiger 2014 MitoPathways.

More details: »Respiratory complexes - more than five

» O2k-Publications: Q-junction effect

» Keywords

Specific

» Complex III

» Convergent electron flow

General

» Categories of SUIT protocols

» Choline dehydrogenase

» Complex I

» Complex II

» Dihydro-orotate dehydrogenase

» Electron-transferring flavoprotein complex

» Electron transfer system

» F-junction

» Glycerophosphate dehydrogenase complex

» N-junction

» NS-linked electron flow

» Pathway control states

Related MitoPedia pages

Electron transfer system, ET-pathway

» Electron transfer system

» Q-junction

Pathway control states

» Pathway control state

Coupling control state E

ET capacity

» Noncoupled respiration

» Is respiration uncoupled - noncoupled - dyscoupled?

@@ Line 1: / Line 1: @@
 {{MitoPedia
 |description=[[File:SUIT-catg FNSGp.jpg|right|300px|Q-junction]]
-The '''Q-junction''' is a junction for [[convergent electron flow]] in the [[electron transfer system]] (ETS) from type N substrates and mt-matix dehydrogenases through [[Complex I]] (CI), from type F substrates and FA oxidation through [[electron-transferring flavoprotein complex]] (CETF),  from succinate (S) through [[Complex II]] (CII), from glycoreophosphate (Gp) through [[glycerophosphate dehydrogenase complex]] (CGpDH), from choline through [[choline dehydrogenase]], from dihydro-orotate through [[dihydro-orotate dehydrogenase]], and other enzyme complexes into the Q-cycle (ubiquinol/ubiquinone), and further downstream to [[Complex III]] (CIII) and CIV. The concept of the Q-junction, with the [[N-junction]] and [[F-junction]] upstream, provides the rationale for defining [[pathway control state]]s and [[categories of SUIT protocols]].
+The '''Q-junction''' is a junction for [[convergent electron flow]] in the [[electron transfer system]] (ET-pathway) from type N substrates and mt-matix dehydrogenases through [[Complex I]] (CI), from type F substrates and FA oxidation through [[electron-transferring flavoprotein complex]] (CETF),  from succinate (S) through [[Complex II]] (CII), from glycoreophosphate (Gp) through [[glycerophosphate dehydrogenase complex]] (CGpDH), from choline through [[choline dehydrogenase]], from dihydro-orotate through [[dihydro-orotate dehydrogenase]], and other enzyme complexes into the Q-cycle (ubiquinol/ubiquinone), and further downstream to [[Complex III]] (CIII) and CIV. The concept of the Q-junction, with the [[N-junction]] and [[F-junction]] upstream, provides the rationale for defining [[pathway control state]]s and [[categories of SUIT protocols]].
 |info=[[Gnaiger 2009 Int J Biochem Cell Biol]], [[Gnaiger 2014 MitoPathways]]
 }}
@@ Line 52: / Line 52: @@
 == Related MitoPedia pages ==
-::* '''Electron transfer system, ETS'''
+::* '''Electron transfer system, ET-pathway'''
 ::::» [[Electron transfer system]]
 ::::» [[Q-junction]]
@@ Line 60: / Line 60: @@
 ::* '''Coupling control state ''E'''''
-::::[[File:E.jpg |link=ETS capacity]] [[ETS capacity]]
+::::[[File:E.jpg |link=ETS capacity]] [[ET capacity]]
 ::::» [[Noncoupled respiration]]
 ::::» [[Uncoupler#Is_respiration_uncoupled_-_noncoupled_-_dyscoupled.3F |Is respiration uncoupled - noncoupled - dyscoupled?]]