La teoría quimiosmótica y la síntesis de ATP en la mitocondria

Presentación del tema: "La teoría quimiosmótica y la síntesis de ATP en la mitocondria"— Transcripción de la presentación:

1 La teoría quimiosmótica y la síntesis de ATP en la mitocondria
José G. Sampedro Instituto de Física, UASLP

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4 Typical prokaryotic (left) and eukaryotic (right) cells.
W. Ford Doolittle Nature 392, 15-16, 1998

5 The endosymbiont hypothesis for the origin of mitochondria (1970)
W. Ford Doolittle Nature 392, 15-16, 1998

6 Endosymbiosis theory (Lynn Margulis, 1970’s)
Model for origin of eukaryotes (A) endomembrane system of eukaryotes may have evolved from specialized infoldings of plasma membrane of ancestral prokaryotes (B) chloroplasts are descendants of photosynthetic prokaryotes, probably cyanobacteria - proposed ancestors of mitochondria were endosymbiotic bacteria that were aerobic heterotrophs a. may have first gained entry into larger cells as undigested prey or internal parasites Be a good skeptic! Where’s the evidence?

7 Lynn Margulis

8 Topology of mitochondrial inner membranes
Carmen Manella, 2008

9 Dr. Carmen Manella Topología de la membrana interna mitocondrial

10 García JJ, 2006 Facultad de Química, UNAM

11 Mitochondrial volume homeostasis mediated by K+ transport and the PTP
Mitochondrial volume homeostasis mediated by K+ transport and the PTP. The scheme summarizes the role of K+ fluxes and PTP opening in mitochondrial volume homeostasis. Kc, potassium channels; ETC, electron transfer chain; Mkh1, essential mitochondrial KHE factor; Δψ, mitochondrial membrane potential difference; PTP, permeability transition pore

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13 Cadena transportadora de electrones

14 Cadena transportadora de electrones

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16 La teoría quimiosmótica (1961)
Peter Mitchel

17 Acoplamiento de la respiración con la síntesis de ATP

18 desacoplamiento de la respiración de la síntesis de ATP!

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25 hidrólisis ATP → ADP + Pi

26 ATP → ADP + Pi Rotation of the actin filament attached to the ε subunit in the presence of 2 mm ATP. Rotation of the actin filament attached to the ε subunit in the presence of 2 mm ATP. a, an example of sequential images of a rotating actin filament attached to the ε subunit in α3β3γεSA. Length of the filament from rotational axis to the tip was 1.6 μm. Rotational rate was 1.0 rps. Time interval between images was 100 ms. Thescale bar denotes 5 μm. b, examples of time course of the rotation of the actin filament. Length of the filaments presented here is 0.5–1.4 μm. Only the filaments that rotated around one end are shown. Each line represents one filament. Solid lines indicate the rotation of the ε subunit in α3β3γεSAwhile dotted lines and broken lines indicate the rotation of the γ subunit in α3β3γSA and α3β3γSAε, respectively.c, same as b except that the length of the filaments is more than 1.5 μm. Details of the experiments are described under “Experimental Procedures.” Kato-Yamada Y et al. J. Biol. Chem. 1998;273: ©1998 by American Society for Biochemistry and Molecular Biology

27 síntesis ADP + Pi → ATP Hiroyasu et al, 2004

28 Hiroyasu et al, 2004

29 Luciernaga

30 Hiroyasu et al, 2004

31 Esto ocurre en la grasa parda!

32 Prefiero jugar! sip!

33 y la cobija amá? Quiero mi chambrita!

34 La generación de calor en la grasa parda

35 Bacteria con flagelos

36 La fotofosforilación oxidativa

37 Espectro de absorbencia de la luz

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39 El acoplamiento del transporte de electrones a la foto-fosforilación oxidativa

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