L26 Oxidative Phosphorylation Flashcards
Why do we need O2?
To release energy from NADH and FADH2
Energy from electrons is used to drive protons out of the matrix creating a concentration gradient or…
Proton motive force
Protons move back into the matrix through…
a) The inner membrane
b) The outer membrane
c) Potassium leak channel
d) ATP synthase
d) ATP synthase
The electron transport chain (ETC) contains ? complexes…
4
Complex I is…
NADH-Q reductase complex
NADH-Q reductase first transfers 2 high energy electrons from…
NADH → FMN
NADH-Q reductase transfers electrons from FMNH2 to a series of…
Iron-sulphur clusters
In NADH-Q, electrons are transferred from iron-sulphur clusters to…
Coenzyme Q (ubiquinone)
Complex III is the…
Cytochrome C Reductase complex
Cytochrome C reductase complex transfers how many protons into the intermembrane space?
4
NADH-Q reductase transfers how many protons into the intermembrane space?
4
In the ETC, electrons:
a) move between matrix and intermembrane space
b) remain within the membrane
c) remain on the matrix side
d) remain on the intermembrane side
b) remain within the membrane
Complex IV is the…
Cytochrome C Oxidase complex
Cytochrome C Oxidase complex pumps how many protons across the membrane?
4
Cytochrome C Oxidase complex uses 4 protons to reduce…
O2 → H2O
Cytochrome C Oxidase complex transfers how many electrons to O2?
4
In total, how many protons are removed from the matric (net)?
-16
In total, how many protons are pumped across to the intermembrane space (net)?
+12
In total, how many electrons are added to the membrane (net)?
+4
Which substances may cause problems with oxidative phosphorylation (3)…
- Carbon monoxide
- Cyanide
- Salicylate
Mitochondrial defects may cause problems with oxidative phosphorylation. These are inherited…
Maternally
Salicylate disrupts oxidative phosphorylation by causing…
Pores to form in the mitochondrial membrane. Protons are able to leaks through without passing via ATPase
Cyanide disrupts oxidative phosphorylation by…
Binding irreversibly to Complex IV (Cytochrome C oxidase) which blocks oxidative phosphorylation
Carbon monoxide disrupts oxidative phosphorylation because it…
Binds irreversibly to haemoglobin, reducing the amount of oxygen available to cells
Oxidative phosphorylation takes NADH and FADH2 from glycolysis and the citric acid cycle to generate…
30ATP + 6H2O
Electrons flow down the ETC from carrier molecules to O2 by an…
Electron-motive force
Uneven distribution of protons generates:
a) pH gradient
b) transmembrane electrical potential
c) Proton-motive force
d) all of the above
d) all of the above
Proton-motive force as a result of the pH gradient and transmembrane electrical potential (more H+ on one side, more +)
The ETC protein complexes are located in the…
Mitochondrial inner membrane
