5Thylakoid membrane contains chloroplastH+ATPChloroplastsdouble membranestromafluid-filled interiorthylakoid sacsgrana stacksThylakoid membrane containschlorophyll moleculeselectron transport chainATP synthaseH+ gradient built up within thylakoid sacthylakoidouter membraneinner membranegranumstromathylakoidA typical mesophyll cell has chloroplasts, each about 2-4 microns by 4-7 microns long.Each chloroplast has two membranes around a central aqueous space, the stroma.In the stroma are membranous sacs, the thylakoids.These have an internal aqueous space, the thylakoid lumen or thylakoid space.Thylakoids may be stacked into columns called grana.
7Pigments Pigments: molecules that absorb visible light Each pigment has a characteristic absorption spectrum, the range it is capable of absorbing.--chlorophyll a – primary pigment--chlorophyll b – secondary pigment-- carotenoids – accessory pigments
9Two stages of photosynthesis: Light-dependent reactionsRequires light as a source of energyStep 1: chlorophyll uses energy from sun to split water moleculesStep 2: water molecules split into H & OStep 3: O2 released to atmosphereStep 4: chlorophyll stores some light energy in ATP
10Photo phosphoryl ation Using lightAdding a phospate groupLight energy is used to add a high-energy phosphate group to a carrier molecule.A process
11Light Reactions produces ATP produces NADPH H2OATPO2lightenergy+NADPHH2Osunlightproduces ATPproduces NADPHreleases O2 as a waste productEnergy BuildingReactionsNADPHATPO2
14Light-Independent reactions (Calvin Cycle) Part of photosynthesis that doesn’t require lightStep 1: hydrogen which split from H2O combines with CO2 using energy stored in ATPStep 2: this combination forms glucose (C6H12O6)Step 3: water is formed (byproduct)
15Making SugarThe energy captured in the Lt-Dep is now used to fix CO2 and make sugar.Stage 1. Fix CO2 to RuBP.Stage 2. Generater PGAL then sugar.Stage 3. Regenerate RuBP.
16Calvin Cycle builds sugars uses ATP & NADPH recycles ADP & NADP CO2 C6H12O6+NADPATPNADPHADPCO2builds sugarsuses ATP & NADPHrecycles ADP & NADPback to make more ATP & NADPHADPNADPSugar BuildingReactionsNADPHATPsugars
17Putting it all together CO2H2OC6H12O6O2lightenergy+H2OCO2Plants make both:energyATP & NADPHsugarssunlightADPNADPEnergy BuildingReactionsSugar BuildingReactionsNADPHATPO2sugars
21Energy cycle ATP Photosynthesis Cellular Respiration sun CO2 O2 H2O even though this equation is a bit of a lie… it makes abetter storysunPhotosynthesisCO2H2OC6H12O6O2lightenergy+H2OplantsCO2glucoseO2animals, plantsCO2H2OC6H12O6O2ATPenergy+Cellular RespirationATPThe Great Circle of Life,Mufasa!