BIO 151 1nd Edition Lecture 11 Outline of Last Lecture - Oxidative phosphorylationo Electron transporto ATP synthesis via chemiosmosis- Accounting summary- Anaerobic respirationo NAD+ RegenerationOutline of Current Lecture - Chloroplastso Overview- Calvin cycleo Carbon fixation-Rubiscoo Sugar synthesis- Light-dependent reactionso PhotosynthesisCurrent Lecture- Chloroplasts: organelle class-plastid; green formo 3 membranes:  Outer Inner Thylakoids- Grana: stacked version- Unstackedo 3 different aqueous spaces Intermembrane space Stroma: main aqueous compartment Thyloakoid lumen: inside spaceo Evidence for an origin through endosymbiosis Plastids have (has prokaryotic background like mitochondria)- Multiple copies of small circular DNA- Smaller (70s, bacteria size) ribosomes- Genes related to the genes cyanobacteriaThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Unusual lipids in their membrane- Divide by splitting in half- Oxygenic photosynthesis:o Overall reaction: 6CO2 +12H2O+light energyC6H12O6 +6O2 +6H2Oo Photosynthesis occurs in: Photosynthetic bacteria  several types Photosynthetic eukaryotes algae (in cholorplasts*); plants (in chloroplasts*)- *descended from cyanobacteria, oxygen-producing type of photosynthesisProcess Cellular compartment ProductsCalvin Cycle Stroma (chloroplast) e- added to carbon skeletoncreated by CO2, producing sugarsLight reactions Chloroplast membrane (thylakoids)Light energy is captured andused to produce high energy e- and ATP by chemiosmosis- Calvin cycleo Involves carbon fixation (1st step) Inorganic C (CO2)  inorganic C Rubisco: (most abundant enzyme on earth)- real name: Ribulose Bisphosphate Carboxylase- 5C (Ribulose)+ 1C(CO2)  6C (unstable) 2x3C(1st stable intermediate)o High cost in electrons and energy  Energy costs: 9ATP/3CO2 (6ATP 6ADP) Electron cost: 6NADPH + H+ (NADPH6NADP+ +Pi)o Main product of calvin cycle per 3CO2 1 3C sugar: glyceraldehyde 3-phosphate CO2 is reduced to sugar- Light absorption, primary pigment=chlorophyllo Porphyrin ring: holds eio Hydrocarbon Tail- Chlorophyll-binding proteinso Two types: Chlorophyll a and Chlorophyll bo Green because of wavelengths Measuring what chlorophyll absorbs: absorbs in blue and red (two peaks) Chlorophyll doesn’t absorb greens green bounces off and hits your eye Carotenoids: secondary pigment, doesn’t absorb yellow-red, so in the winter when chlorophyll dies, leaves are red-yellow- Photosystems: pigment-protein complexeso Two major photosystems: PSI: photosystem 1 PSII: photosystem 2o Both systems have similar system structures Central core complex= Reaction center- Chl a rich Antenna complexes: spread out receptive surface, increases efficiency of light absorption, adjustable solar panels that can change size- Chl-b rich- Contains most of chlorophyll- Plants in shadelarge antenna’smore chlorophyllmore greeno Both PSI and PSII differ in wavelength absorption PSI: max absorption at wavelength 700nm; lower energy PSII: max absorption at 680 nm; higher energy- Patterns of e- flowo Stacked region PSI and PSII are present Linear e- flowo Unstacked region PSI Cyclic e-