Presentation on theme: "Using Light to Make Food"— Presentation transcript:
1 Using Light to Make Food PHOTOSYNTHESISUsing Light to Make Food
2 It provides food for virtually all organisms Photosynthesis is the most important chemical process on earth because:It provides food for virtually all organismsSWEET!!!!
3 BIG PICTURE: Photosynthesis Light energy is used to make sugar and other food molecules from carbon dioxide and water
4 6 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)
5 Autotrophs“Self-feeders” Make their own foodAlso referred to as: Producers = produce the biosphere’s food supply
36 What happens here? Assembles sugar molecules using CO2 Light Dependent Reaction (LDR)Converts light energy to chemical energy + O2Light Independent Reaction (LIR)Assembles sugar molecules using CO2
37 Where does energy come from? Light Dependent Reaction LDRUses light energyLight Independent Reaction LIR(Calvin Cycle)uses ATP and NADPH (from LDR)
38 PSI and PSIIPSI and PSII animationAnother PSI and PSII animation
39 Where is it located in the cell? LDRoccurs in thylakoid membranes of chloroplast’s granaLIR (aka Calvin cycle)occurs in stroma of chloroplast
40 Final Products of Each?LDRATP and NADPHAlso O2LIRsugar
41 Carbon fixation = FIXATION = make in a usable form NEW VOCAB. WORDCarbon fixation =incorporation of carbon into an organic molecule (useable)EXAMPLE: CO2 into C6H12O6FIXATION = make in a usable form
43 Pigments in Plants Pigments are light-absorbing molecules Different pigments absorb or reflect different colors
44 Wavelength Chlorophyll a wavelengths absorbed: blue-violet and red Reflects: grass greenWavelength
45 An accessory chlorophyll in plants Chlorophyll bAbsorbs: blue and orangeReflects: yellow-greenAn accessory chlorophyll in plants
46 Other pigments in plants Carotenoids-orangeAbsorb: blue-greenReflect: yellow-orange
47 FYI 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
67 Cyclic 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
69 Animations 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+
74 What process drives each? NADPH formingATP formingO2 formationRedox and ETCChemiosmosis
75 NOTE: Final Electron Acceptor is NADPHNot Oxygen (Oxygen is given off) in Light Reaction of Photosynthesis
76 AnimationMaking Oxygen (You’ll love the noises)(I hate ‘em)
77 Chemiosmosis Again#1 Remember chemiosmosis in cellular respiration, well, here it is again.
78 7.9 Question #2 PS I: Forming H+ ions to form ATP By chemiosmosis
79 7.9 #3 There would now be more H+ ions located: Came from the stroma and went to the thylakoid interior
80 7.9 #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.
84 Can 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.
85 Animation 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
86 View MePhotosynthetic Electron Transport and ATP Synthesis
98 QUIZ TIME: structuresThe light reactions (LDR) of photosynthesis occur in the __________, and the Calvin cycle (LIR) occus in the __________ of the chloroplast.
99 ANSWERThe light reaction occurs in the thylakoid membranes and the dark reaction occurs in the stroma.
100 Which 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
101 B. water + carbon dioxide ---> oxygen + glucose + water ANSWERB. water + carbon dioxide ---> oxygen + glucose + water
102 In what organelle does photosynthesis occur? A. the nucleus B. chloroplasts C. the vacuole D. the cell wall
106 QUIZ 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
107 ANSWERE. a higher concentration of H+ ions inside vs. outside the thylakoid membranes
108 QUIZ 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
110 QUIZ 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
111 C. oxygen concentration ANSWER:C. oxygen concentration
112 QUIZ 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
113 HINT: Distribution of H+ ions Light Rxmore insideDark RxEven in and out
114 More concentrated with H+ ions ANSWERMore concentrated with H+ ions
115 QUIZ TIMEWhich of the following is produced during photosynthesis? A. carbon dioxide B. lactic acid C. DNA D. PGAL
117 QUIZ 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
118 C. water molecules split during the light reactions ANSWERC. water molecules split during the light reactions
119 QUIZ 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
120 A. solar energy is converted to chemical energy ANSWERA. solar energy is converted to chemical energy
142 QUIZ 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
143 ANSWERa higher concentration of H+ ions inside vs. outside the thylakoid membranes
144 QUIZ 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