Photosynthesis What is it Where it occurs How

Photosynthesis • What is it ? • Where it occurs ? • How is its important ? • How to measure ?

Photosynthesis ประกอบดวย 3 กระบวนการยอย • CO 2 diffusion A = Cg d[CO 2[ • Photochemical process (light reaction( 4 H 2 O + 2 ADP+2 NADP+ +2 pi O 2+2 H 2 O+2 ATP+2 NADPH +2 H+ • Biochemical process 3 CO 2+9 ATP+6 NADPH+6 H+ P+6 NADP+9 ADP+8 Pi+3 H 2 O triose-

The overall chemical reaction • CO 2 + 2 H 2 O light / atenna ADP +Pi +NADP+ CO 2 (CH 2 O) + H 2 O + O 2 PSII PSI Cytochrome enzymes/ stroma Ru. BPcarboxylase : CO 2 receptor O 2 + H+ +Pi ATP + NADPH (CH 2 O)

CHLOROPLAST • 1 - 10 mm • Lamellae (membranes) : light reaction – stroma lamella (double lamella) – grana lamella (stacked lamella) • Stroma : dark reaction

Leaf anatomy of C 3 vs. C 4 plants

Chloroplast and Chlorophyll structure

Electron transportation • Chlorophyll a , b Carotenoid • Reaction centers : absorbed PHOTONS from light energy • PSII : ground stage excited stage • PSI : Q , Photophosphorylation

Energy diagram of the photosynthetic electron transport system Light O 2 Chlorophyll a/b Chlorophyll a P 680 Electron transfer P 700 Electron transfer NADPH ATP H 2 O Photosystem II Photosystem I

Energy diagram of the photosynthetic electron transport Redox potential Fd-Ub -800 e- -600 Fd -400 -200 Solar radiation e ADP 400 e- Cty f ATP 600 800 Solar eradiation Q 0 200 NADP+ H 2 O Photo system II H+ O 2 NADPH Photo system I CO 2 reduction

Radiation vs Photons • E = hv = speed of light/wave length • E = energy content of the quantum (J/quantum( • h = Planck ‘s constant (6. 626 x 10 -34 J s( ) 700 600 ) 14. 3 16. 7 ) 4. 5 5 ) 2. 9 3. 3 500 400 nm( 20 25 x 103 cm-1( 6 7. 5 x 1014 s-1( 4 5 x 10 -19 J quantum-1(

Conversion factors for energy units used in the text • • • 1 electron volt (e. V) = 1. 602 x 10 -19 J 1 watt = 1 J s-1 1 k. Wh = 3. 6 x 106 J 1 Joule = 0. 239 calories 6. 242= x 1018 e. V 1 cal. = 4. 184 J 1 k. J mol quantum -1 = 1. 036 x 10 -2 e. V Plank’s constant = 6. 62 x 10 -34 Js 4. 136= x 10 -15 e. Vs 1 mol quantum of photon contains Avogadro’s number 6. 023 x 1023 particles = 1 Eistein

Radiation & Light

Carbondioxide fixation Biomass or Dry weight = Photosynthesis Respiration - Dead - Translocation Carbon Balance • C 3 species : Calvin cycle ; RUBP 3 -PGA • C 4 species : Hatch & Slack cycle ; PEP Oxaloacetic Acid etc. • Crussulation Acid Metabolism (CAM) : CO 2 fixed during night C 3 vs C 4 : Kranz anatomy

C 3 C 4 and CAM plant PEP Carboxylase CO 2 C 4 Organic acids PEP C 3 C 4 CAM Ru. BP Carboxylase CO 2 C 3 acids CO 2 PGA RUBP Mesophyll Bundle sheath Dark Light (CH 2 O)

Cellular respiration • The process by which active cells obtain energy. It occurs in mitochondria, there are two coditions : aerobic & anaerobic respiration. • The obtained energy was used for maintenance and growth of the cell or organ. • Growth respiration : catabolism provides the energy required for biosynthesis and constructive reactions leading to form cellular products used in the crop growth

Aerobic respiration has 3 stages: C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O + energy Sucrose NAD+ Glycolysis Pyruvic acid e transport chain TCA Oxidative phosphorylation Krebs’ cycle NADH, + ADP NADH, ATP O 2 H 2 O

Respiration • MITOCHONDRIA • C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O +637 kcal • Glycolysis : anaerobic respiration • aerobic respiration : Kreb’s cycle ; Oxidative phosphorylation

Major plant metabolisms O 2 STRUCTURAL compounds • cellulose • hemicellulose • pentosans • pectin, ect. Chloroplast : Photosynthesis STORAGE compounds • starch • fructosans • proteins • lipids, ect. ACTIVE CELL compounds • nucleic acids • enzymes • cytochrome • chlorophyll • phospholipids, ect. Synthesis / Translocation Glycolysis CO 2 ATP, NADP Mitochondria : Respiration; Krebs cycle O 2 CO 2

Photosynthesis vs Respiration • Photophosporylation • Oxidative phosphorylation • NADPH formed • NADP formed • CO 2 reduction • CO 2 as substrate • CO 2 is product • H 2 O as substrate • H 2 O is product • O 2 is substrate • CH 2 O is product • (CH 2 O)n is substrate and product

Photosynthesis vs Respiration if. …… • Down • Up • Down if + CO 2 • Up • Up if + light • Up • Up if + temperature • Stop • Burst if dark if + O 2

Environments SOIL CLIMATE AGRONOMY Character of CROPS Water route Photosynthesis Yield potential Etr/Etm Pst * Etr/Etm -Res P pot X HI

BAMnut model (Azam-Ali Sayed et. al, 2001. A Global Mapping Systems for Bambara Groundnut Production. FAO Agricultural Information Management Series( Weather data Water limited growth (WLG( Radiation limited growth (LLG( seed Intercepted radiation Bambara groundnut Water uptake Soil water Root Pod. W Leaf. W Root. W Shoot. W