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1、植物生理学,Plant Physiology,Biochemistry & Molecular Biology of Plants Bob B. Buchanan Wilhelm Gruissem Russell L. Jones,植物学报 植物生理学 植物生理学通信 Plant Physiology Plant Cell Plant Science Planta Annual Review of Plant Physiology and Plant Molecular Biology,Part 1 Photosynthesis,1.1 Overview of Photosynthesis 1
2、.1.1 Photosynthesis is a biological oxidation-reduction process. Reaction 1.1: Photosynthesis CO2+2H2A(CH2O)+2A+H2O,ljtang:,Reaction1.2: Oxygenic Phototsynthesis CO2+2H2O(CH2O)+O2+H20,Reaction1.3:Photosynthetic sulfur reduction,CO2+2H2A(CH2O)+2S+H2O,1.1.2 In photosynthetic eukaryotes, photosynthesis
3、 takes place in the chloroplast, a specialized organelle,Chloroplast, a double-membrane system, consist of an out envelope and inner envelope. The internal membrane system , known as the thylakoids, contains granal thylakoids and stroma thylakoids. The thylakoid membranes are all interconnected and
4、enclose an internal space, the lumen.,1.1.3 Photosynthesis requires the coordination of two phases: light reactions and carbon-linked reactions,Light reactions: produce O2, ATP, and NADPH. Carbon reduction cycle: reduce CO2 to carbohydrate on consuming the ATP and NADPH. The conception that water ox
5、idation and CO2 reduction were not obligately linked was first advanced in 1930s by Robert Hill . Reaction 1.4: Hill Reaction 2H2O+2AO2+2H2A,1.2 Light Absorption and energy conversion. 1.2.1 Light is absorbed by pigment molecules. PigmentPigment*,number of products formed photochemically Equation 1.
6、2.1: Quantum Yield = - Number of quanta absorbed,1.2.2 Almost all photosynthetic organisms contain chlorophyll or a related pigment.,Plants, Algae and Cyanobacteria: chlorophyll a or chlorophyll b. Anaerobic photosynthetic bacteria: bacteriochlorophyll a. Chlorophylls have a porphyrin ring structure
7、 that contains a central Mg atom coordinated to the four modified pyrrole rings. Chlorophyll molecules also contain a long hydrocarbon tail that makes the molecules hydrophobic. Various chlorophylls differ in their substituents around the ring structure.,Biosynthesis of chlorophylls and hemes.,1.2.3
8、 Carotenoids and xanthophylls participate in light absorption and photoprotection.,1.2.4 Absorption spectra of chlorophylls and other photosynthetic pigments,1.2.5 Red algae and Cyanobacteria contain accessory pigments that absorb green light.,1.3 The reaction center complex . 1.3.1 Reaction centers
9、 are integral membrane protein complexes involved in conversion of light energy into chemical products. 1.3.2 Reaction centers contain both special chlorophyll and electron acceptor molecules involved in energy conversion. 1.3.3 The structure of a reaction center from a photosynthetic bacterium has
10、been determined.,1.3.4 The kinetics of primary charge separation events are understood in great detail.,1.3.5 Oxygenic photosynthetic organisms contain two photochemical reaction centers, PSI and PSII,1.3.5.1 Structure model of the PSII reaction center.,1.3.5.2 Structure model of the PSI reaction ce
11、nter.,1.4 The Photosystem,1.4.1 A photosystem contains a photochemical reaction center and multiple antennae ( auxiliary light-harvesting pigment-protein complexes). 1.4.2 Most oxygenic photosynthetic organisms contain chlorophyll a/b proteins as their principal antennae.,Table 1.4.2 Properties of l
12、ight-harvesting chlorophyll protein complexes,Complex Chl a/b ratio Gene Mol. Mass(kDa) Light-harvesting complexes (LHC) associated with PS LHC-a 2.0-3.1 lhca3 20.5 (LHC-680) lhca2 18 LHC-b 2.2-4.4 lhca1 20 (LHC-730) lhca4 20 Light-harvesting complexes associated with PS LHC-a (CP29) 4.0 lhcb4 29 LH
13、C-b 1.35 lhcb1 27-28 LHC-c (CP26) 2.9 lhcb5 26.5 LHC-d (CP24) 1.51 lhcb6 24,1.4.2 The organization of pigments in PS and PS.,1.4.3 The light-harvesting antennae of organism that contain phycobilins,Reaction 1.4.3 Energy transfer in a phycobilisome,Phycoerythin(PC) Phycocyanin(PE) Allophycocyanin(APC
14、) Chl a,1.5 Organization of thylakoid membrane1.5.1 Protein complexes of the thylakoid membrane exhibit lateral heterogeneity.,1.5.2 Phosphorylation of LHC- may influence the distribution of energy between PS and PS,1.6 Electron transport pathways in chloroplast membranes1.6.1 The chloroplast noncyc
15、lic electron transport chain produces O2,NADPH, and ATP and involves the cooperation of PS and PS,1.6.2 Photosystem stoichiometry variesby species and is influenced by light environment.,Table 1.6.2 Stoichiometry of the photosystems in different oxygen-evolving systems and in response to changes in light quality _ System PS/PSratio Cyanobacteria 0.4 Red algae 0.4 Green algae 1.4 Tobacco mutant su/su 2.7 Pea chloroplasts From plants grown in PS light (550-66
