1. Lecture 10 Slides rh

2. A science family tree…
Albert Lehninger
Eugene Kennedy
Christian R. H. Raetz
Randolph Y. Hampton

3. (plural mitochondria)
The mitochondrion
(plural mitochondria)
fig 19-1

4. fig 19-1

5. mitochondria (plural…mitochondrion is singular)
outer membrane
porins permeable to MW<5000
inner membrane
impermeable to most small molecules
respiratory chain complexes
ATP-ADP translocases, other transporters
ATP synthase
impermeable to most small molecules
matrix
pyruvate dehydrogenase complex
Krebs cycle enzymes
many other things (later and before)

6. NADH: a universal electron carrier

7. cofactor electron acceptors
nicotinamide nucleotide-linked dehydrogenases
NAD+ or NADP+ are acceptors
loosely bound, freely dissociable
true carriers
flavoproteins
FMN and FAD isoalloxazine acceptors
tightly bound to enzymes
single or two electron transfers

8. 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
cytochromes
heme cofactors
most are integral membrane proteins (not c)
iron-sulfer proteins
multiple types of clusters

9. Drugs for studying e- transport order
fig 19-6

10. 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

11. Ubiquinone
(coenzyme Q)
fig19-2

14. 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
cytochromes
heme cofactors
most are integral membrane proteins (not c)

15. heme cofactors
Fe+2
Fe+3
+ e-
fig19-3

16. Spectral properties of cytochromes
fig 19-4

17. 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
cytochromes
heme cofactors
most are integral membrane proteins (not c)
iron-sulfer proteins
multiple types of clusters

18. Iron-sulfur clusters in proteins
fig19-5

19. how do we know it’s a chain?
Respiratory chain
Electron transport chain
how do we know it’s a chain?
order suggested by E values
inhibitor studies on A and D composition
direct biochemical studies (!!)

20. Reduction potentials in respiration

21. order suggested by E values…

22. inhibitor studies on A and D composition…
fig 19-6

23. Hard-core
biochemistry
for study of
respiratory
chain
fig 19-7

24. Don’t waste clean thinking on dirty enzymes a message from Efraim
fig19-7

25. direct
biochemical
studies (!!)…
fig19-7

26. direct biochemical studies (!!)…
fig19-7

28. I NADH dehydrogenase
“Hp”
fig19-9

29. II succinate dehydrogenase
fig19-8

30. III
ubiquinone:
cytochrome c
oxidoreductase
fig19-11

31. III
ubiquinone:
cytochrome c
oxidoreductase
fig19-11

34. IV cytochrome oxidase
fig19-13

35. a Cu-S complex!
fig19-13

36. fig19-14

37. electron transport chain
fig19-16 simplified

38. electron transport chain
fig19-16

39. fig19-17

40. electron transport chain
fig19-16

41. fig19-17

42. proton-motive force
23.6 kJ/mole H+

43. the coupling question…
chemiosmotic hypothesis!

44. the coupling question…
chemiosmotic hypothesis!