Download ATP synthesis in chloroplast

國立台灣大學生物資源暨農業學院
植物光生態生理學
(Plant Photo-ecophysiology)
第7章 ATP的合成
楊棋明 博士
中央研究院植物研究所暨生物多樣性研究中心
Email: [email protected]
Tel: 02-27821258#612, 613
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Four stages of photosynthesis in higher plants
Stage 1: absorption of light
Thylakoid membrane
light
Chl
2H2O
Chl*
light
O2＋4H＋＋4e－
Stage 2: electron transport and
generation of a proton-motive force (pmf)/pH gradient
2H2O＋2NADP＋
2H＋＋2NADPH＋O2
Stage 3: synthesis of ATP
ADP3－＋Pi2－
Stroma
light
ATP4－
Stage 4: carbon fixation
6CO2＋18ATP4－＋12NADPH＋12H2O
C6H2O＋18ADP3－＋18Pi2－＋12NADP＋＋6H＋
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Chemical structure of ATP, ADP and AMP and their energy
ATP＋H2O
ADP＋H2O
AMP＋H2O
ADP＋Pi＋ 7.3kcal/mol
AMP＋Pi＋7.3kcal/mol
Adenosine＋Pi＋3.4kcal/mol
Adenine
7.3kcal/mol
3.4kcal/mol
Ribose
7.3kcal/mol
ATP
ADP
AMP
Adenosine
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ATP synthesis in chloroplast (1): the chemiosmotic hypothesis
Pete Mitchell (UK) in 1961 proposed a chemiosmotic hypothesis to account for ATP
formation accompanying electron transport in mitochondria and chloroplasts.
Pete Mitchell was awarded the Nobel Prize in 1978.
Paul Boyer (USA) and John Walker (UK), elucidating the ATPase structure and
function, were awarded the Nobel Prize in 1997.
The Chemiosmotic Hypothesis:
Intact membranes are almost impermeable to the passive flow of protons.
The electron donors and acceptors of electron and proton are arranged vectorially
in the membrane.
During photosynthetic electron transport, protons are translocated from the external
medium (stroma) into the osmotic space of the intra-thylakoid membrane.
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ATP synthesis in chloroplast (2):
the chemiosmotic hypothesis
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ATP synthesis in chloroplast (3):
ATPase or ATP synthase/ coupling factors/ CF0CF1 complex
Paul Boyer (USA) and John Walker (UK), elucidating the ATPase
structure and function, were awarded the Nobel Prize in 1997.
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Inside-out and outside-in of mitochondrial and chloroplast
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Construction of artificial ATP synthesis system
lumen
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ATP synthesis (4): bacteria, mitochondria, chloroplast
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Comparison of chemiosmosis in mitochondria and chloroplasts
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Subunits and their structures of ATPase
complex in eukaryotes
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(α3β3γδε)
C, chloroplast
N, nucleus
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ATPase in the bacteria, mitochondria, chloroplast
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Rotational model for ATP synthesis
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Experimental evidence
for rotation of ATPase
ATPase is a rotatory motor.
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Mitochondrial ATPase
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Structure and location of ATPase on the thylakoid membrane
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Have you a nice day
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