1 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 Tel: #612, 613

2 Four stages of photosynthesis in higher plants Stage 1: absorption of light Chl Chl* 2H 2 O O 2 ＋ 4H ＋ ＋ 4e － Stage 2: electron transport and generation of a proton-motive force (pmf)/pH gradient 2H 2 O ＋ 2NADP ＋ 2H ＋ ＋ 2NADPH ＋ O 2 Stage 3: synthesis of ATP ADP 3 － ＋ Pi 2 － ATP 4 － Stage 4: carbon fixation 6CO 2 ＋ 18ATP 4 － ＋ 12NADPH ＋ 12H 2 O C 6 H 2 O ＋ 18ADP 3 － ＋ 18Pi 2 － ＋ 12NADP ＋ ＋ 6H ＋ light Thylakoid membrane Stroma

3 Chemical structure of ATP, ADP and AMP and their energy ATP ＋ H 2 OADP ＋ Pi ＋ 7.3kcal/mol ADP ＋ H 2 OAMP ＋ Pi ＋ 7.3kcal/mol AMP ＋ H 2 OAdenosine ＋ Pi ＋ 3.4kcal/mol 7.3kcal/mol 3.4kcal/mol ATP ADP AMP Adenosine Ribose Adenine

4 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  Paul Boyer (USA) and John Walker (UK), elucidating the ATPase structure and function, were awarded the Nobel Prize in 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.

5 ATP synthesis in chloroplast (2): the chemiosmotic hypothesis

6 ATP synthesis in chloroplast (3): ATPase or ATP synthase/ coupling factors/ CF 0 CF 1 complex  Paul Boyer (USA) and John Walker (UK), elucidating the ATPase structure and function, were awarded the Nobel Prize in 1997.

7 Inside-out and outside-in of mitochondrial and chloroplast

8 Construction of artificial ATP synthesis system lumen

9 ATP synthesis (4): bacteria, mitochondria, chloroplast

10 Comparison of chemiosmosis in mitochondria and chloroplasts

11 Subunits and their structures of ATPase complex in eukaryotes (α 3 β 3 γδε) C, chloroplast N, nucleus ★

12 ATPase in the bacteria, mitochondria, chloroplast

13 ★★ ★ ★ ★ ★ Rotational model for ATP synthesis

14 Experimental evidence for rotation of ATPase  ATPase is a rotatory motor.

15 Mitochondrial ATPase

16 Structure and location of ATPase on the thylakoid membrane

17 Have you a nice day