rh lecture 10 slides. a science family tree… albert lehninger christian r. h. raetz eugene kennedy...
TRANSCRIPT
rh
Lecture 10 Slides
A science family tree…
Albert Lehninger
Christian R. H. Raetz
Eugene Kennedy
Randolph Y. Hampton
fig 19-1
The mitochondrion (plural mitochondria)
fig 19-1
mitochondria (plural…mitochondrion is singular)
outer membrane
inner membrane
matrix
• porins permeable to MW<5000
• impermeable to most small molecules• respiratory chain complexes• ATP-ADP translocases, other transporters• ATP synthase
• pyruvate dehydrogenase complex• Krebs cycle enzymes• many other things (later and before)
• impermeable to most small molecules
NADH: a universal electron carrier
cofactor electron acceptorsnicotinamide nucleotide-linked dehydrogenases
flavoproteins
• NAD+ or NADP+ are acceptors• loosely bound, freely dissociable• true carriers
• FMN and FAD isoalloxazine acceptors• tightly bound to enzymes• single or two electron transfers
inner membrane carrier molecules (in the four complexes)
ubiquinone, or coenzyme Q
cytochromes• heme cofactors• most are integral membrane proteins (not c)
• benzoquinone for 1 or 2 electron• freely diffusable in inner membrane• membrane-bound carrier
iron-sulfer proteins• multiple types of clusters
fig 19-6
Drugs for studying e- transport order
inner membrane carrier molecules (in the four complexes)
ubiquinone, or coenzyme Q• benzoquinone for 1 or 2 electron• freely diffusable in inner membrane• membrane-bound carrier
fig19-2
Ubiquinone(coenzyme Q)
inner membrane carrier molecules (in the four complexes)
ubiquinone, or coenzyme Q
cytochromes• heme cofactors• most are integral membrane proteins (not c)
• benzoquinone for 1 or 2 electron• freely diffusable in inner membrane• membrane-bound carrier
fig19-3
heme cofactors
Fe+2
Fe+3 + e-
fig 19-4
Spectral properties of cytochromes
inner membrane carrier molecules (in the four complexes)
ubiquinone, or coenzyme Q
cytochromes• heme cofactors• most are integral membrane proteins (not c)
• benzoquinone for 1 or 2 electron• freely diffusable in inner membrane• membrane-bound carrier
iron-sulfer proteins• multiple types of clusters
fig19-5
Iron-sulfur clusters in proteins
how do we know it’s a chain?
order suggested by E values
inhibitor studies on A and D composition
direct biochemical studies (!!)
Respiratory chainElectron transport chain
Reduction potentials in respiration
order suggested by E values…
fig 19-6
inhibitor studies on A and D composition…
fig 19-7
Hard-corebiochemistryfor study ofrespiratorychain
fig19-7
a messagefrom Efraim Don’t waste
clean thinkingon dirty enzymes
fig19-7
direct biochemical studies (!!)…
fig19-7
direct biochemical studies (!!)…
fig19-9
I NADH dehydrogenase“Hp”
fig19-8
II succinate dehydrogenase
III ubiquinone:cytochrome c oxidoreductase fig19-11
fig19-11
III ubiquinone:cytochrome c oxidoreductase
fig19-13
IV cytochrome oxidase
fig19-13a Cu-S complex!
fig19-14
fig19-16 simplified
electron transport chain
fig19-16
electron transport chain
fig19-17
fig19-16
electron transport chain
fig19-17
proton-motive force
23.6 kJ/mole H+
the coupling question…
chemiosmotic hypothesis!
the coupling question…
chemiosmotic hypothesis!