Presentation on theme: "Using Light to Make Food"— Presentation transcript:
1Using Light to Make Food PHOTOSYNTHESISUsing Light to Make Food
2It provides food for virtually all organisms Photosynthesis is the most important chemical process on earth because:It provides food for virtually all organismsSWEET!!!!
3BIG PICTURE: Photosynthesis Light energy is used to make sugar and other food molecules from carbon dioxide and water
46 H2O + 6 CO2 ----------> C6H12O6+ 6 O2 Chemical Reactionsunlight6 H2O + 6 CO > C6H12O6+ 6 O2How does this equation compare to the cell respiration one?Photosynthesis: An Overview of Photosynthesis (click)
5Autotrophs“Self-feeders” Make their own foodAlso referred to as: Producers = produce the biosphere’s food supply
43Pigments in Plants Pigments are light-absorbing molecules Different pigments absorb or reflect different colors
44Wavelength Chlorophyll a wavelengths absorbed: blue-violet and red Reflects: grass greenWavelength
45An accessory chlorophyll in plants Chlorophyll bAbsorbs: blue and orangeReflects: yellow-greenAn accessory chlorophyll in plants
46Other pigments in plants Carotenoids-orangeAbsorb: blue-greenReflect: yellow-orange
47FYI Why do leaves change color? Chlorophyll breaks down and exposes the other colors that were there all along, but were masked by the green chlorophyll.As fall comes there are shorter days of sunlightLess photosynthesis means less food for plants.
48“Absorption of Chlorophyll” DO WORKSHEET“Absorption of Chlorophyll”Photosynthesis: The Action Spectrum for Photosynthesis (experiment link)
66#4 “Photosystem” = PSAntenna molecules + reaction center + primary electron acceptor
67Cyclic Electron Flow (Light RXN) electron acceptorElectron flow through transfer chain sets up conditions for ATP formation at other membrane sites.electron transfer chaine–e–ATPe–Figure 7.12 Page 122
68#5 TWO photosystems: PS I and PS II: absorbs λ (λ = wavelength) PS I -P 700 nm PS II -P 680 nm
69Animations P700 and P680 Animation Making ATP and NADPH (Light Dependent Reaction)
73#2 PS II: Breaking up water The P680 requires an electron, which is taken from a water molecule, breaking the water into H+ ions and O-2 ions.These form the O2 that is released.2 H2O e- + 4H+
74What process drives each? NADPH formingATP formingO2 formationRedox and ETCChemiosmosis
75NOTE: Final Electron Acceptor is NADPHNot Oxygen (Oxygen is given off) in Light Reaction of Photosynthesis
76AnimationMaking Oxygen (You’ll love the noises)(I hate ‘em)
77Chemiosmosis Again#1 Remember chemiosmosis in cellular respiration, well, here it is again.
787.9 Question #2 PS I: Forming H+ ions to form ATP By chemiosmosis
797.9 #3 There would now be more H+ ions located: Came from the stroma and went to the thylakoid interior
807.9 #4The H+ ions move through what port to move back into the stroma?ATP synthase
81#5 Photophosphorylation is the process of converting energy from a light-excited electron into the phosphate bond of an ADP molecule into ATP.This occurs when the electrons from water are excited by the light in the presence of P680.
84Can the Calvin Cycle also be called the “dark reaction?” PEANUT: It does not need light to run, but it can also run during light. So…the “dark cycle” term is not used anymore.
85Animation Noncyclic photophosphorylation (THIS ONE IS MY FAVORITE) Cyclic and Noncyclic Photophosphorylation (first one is very detailed, second one is better for HS)Photosynthetic ETC and ATP Synthesis
86View MePhotosynthetic Electron Transport and ATP Synthesis
98QUIZ TIME: structuresThe light reactions (LDR) of photosynthesis occur in the __________, and the Calvin cycle (LIR) occus in the __________ of the chloroplast.
99ANSWERThe light reaction occurs in the thylakoid membranes and the dark reaction occurs in the stroma.
100Which equation summarizes photosynthesis? A. water + starch ---> glucose + glucose + glucose B. water + carbon dioxide ---> oxygen + glucose + water C. glucose + oxygen ---> water + carbon dioxide + ATP D. glucose + glucose ---> maltose + water
101B. water + carbon dioxide ---> oxygen + glucose + water ANSWERB. water + carbon dioxide ---> oxygen + glucose + water
102In what organelle does photosynthesis occur? A. the nucleus B. chloroplasts C. the vacuole D. the cell wall
106QUIZ TIME The reason why ADP + P form ATP in thylakoid membranes is… A movement of electrons between photosystem II and photosystem I.B oxidation of waterC oxidation of NADPHD absorption of photons by chloroplast pigmentsE higher concentration of H+ inside versus outside the thylakoid membranes
107ANSWERE. a higher concentration of H+ ions inside vs. outside the thylakoid membranes
108QUIZ TIMEWater is broken down and the electrons from water pass through photosystem II and photosystem I before adding e- to:A carbon dioxideB NADP+C plastoquinonesD FADE rubisco
110QUIZ TIMEWhich of the following would have the smallest effect on the rate of photosynthesis in a green plant? A. carbon dioxide concentration B. light intensity C. oxygen concentration D. water available
112QUIZ TIME A. more concentrated with ATP During photosynthetic electron transport, the interior compartment of the thylakoid membranes becomes:A. more concentrated with ATPB. more concentrated with H+ ionsC. less concentrated with H+ ions
113HINT: Distribution of H+ ions Light Rxmore insideDark RxEven in and out
114More concentrated with H+ ions ANSWERMore concentrated with H+ ions
115QUIZ TIMEWhich of the following is produced during photosynthesis? A. carbon dioxide B. lactic acid C. DNA D. PGAL
117QUIZ TIMEAtmospheric oxygen that is inhaled by animals comes from: A. carbon dioxide molecules split during the light reactions B. carbon dioxide split during the dark reactions C. water molecules split during the light reactions D. water molecules split during the dark reactions
118C. water molecules split during the light reactions ANSWERC. water molecules split during the light reactions
119QUIZ TIMEWhat change occurs during photosynthesis? A. solar energy is converted to chemical energy B. kinetic energy is converted to chemical energy C. chemical energy is converted to radiant energy D. water is converted to chemical energy
120A. solar energy is converted to chemical energy ANSWERA. solar energy is converted to chemical energy
142QUIZ TIME The reason why ADP + P form ATP in thylakoid membranes is… A movement of electrons between photosystem II and photosystem I.B oxidation of waterC oxidation of NADPHD absorption of photons by chloroplast pigmentsE higher concentration of H+ inside versus outside the thylakoid membranes
143ANSWERa higher concentration of H+ ions inside vs. outside the thylakoid membranes
144QUIZ TIMEDuring photosynthetic electron transport, the interior compartment of the thylakoid membranes becomes:A. more concentrated with ATPB. more concentrated with H+ ionsC. less concentrated with H+ ions