front 1 early days of photosynthesis | back 1 prokaryotic photosynthesis likely made oxygen in the atmosphere, laying the evolutionary foundation for eukaryotic photosynthesis to develop |
front 2 reaction center | back 2 contains special molecules that can transform light energy into chemical energy |
front 3 antenna pigments | back 3 gather light and bounce energy to the reaction center (e.g. chlorophyll a, chlorophyll b, carotenoids) |
front 4 pigments | back 4 light absorbing molecules in chloroplasts |
front 5 chlorophyll a | back 5 absorb blue-violet and red, directly feeds light reactions, looks green because reflects green light |
front 6 chlorophyll b | back 6 absorbs blue and orange light, looks yellow-green because reflects that light, does NOT directly participate in light reactions but feeds by broadening the range of light a plant can use and giving energy to chlorophyll a |
front 7 carotenoids | back 7 absorb blue-green light, reflect yellow-orange light, some pass light energy onto chlorophyll a while others dissipate excess light energy to stop damage |
front 8 absorption spectrum | back 8 shows how well a certain pigment absorbs electromagnetic radiation, opposite of emission spectrum, light absorbed is plotted as a function of radiation wavelength |
front 9 photon | back 9 fixed quantity of light energy, shorter wavelength = greater energy |
front 10 What happens when a pigment absorbs a photon? | back 10 one electron gain energy, raised from ground to an excited and unstable state, loses excess energy as heat or light as returns to stability |
front 11 chlorophyll solution | back 11 emits heat and reddish photon afterglow (fluorescence) as electrons go from excited to ground |
front 12 primary electron acceptor | back 12 reduced when illuminated chloroplast chlorophyll transfers excited electrons to it, while chlorophyll is oxidized, ATP and NADPH are made |
front 13 photosystem | back 13 chlorophyll a, chlorophyll b, and the carotenoids are clustered together in the thylakoid membrane in 200-300 molecular assembled |
front 14 photosystem 1 | back 14 P700 chlorophyll a, best absorbs 700 nm of red light, works with different proteins from photosystem 2 |
front 15 photosystem 2 | back 15 P680 chlorophyll a, best absorbs 680 nm of orangey-red light, works with different proteins from photosystem 1 |
front 16 photophosphorylation | back 16 when light energy is used to make ATP in autotrophs |
front 17 photolysis | back 17 when water is split into oxygen, hydrogen, ions, and electrons to replenish the thylakoid's electrons |
front 18 light dependent reactions | back 18 occur in the grana of chloroplast (thylakoids) with antenna pigments, water is oxidized so oxygen escapes as gas and H2 goes into the NADP+ electron carrier which turns into NADPH |
front 19 What comes into light dependent reactions? | back 19 water, ADP, NADP+ |
front 20 What comes out of light dependent reactions? | back 20 ATP, NADPH, O2 |
front 21 cyclic phosphorylation | back 21 some plants perform cyclic electron flow, generating only ATP and no NADPH, only in photosystem 1 (once an electron is displaced from the photosystem, it is passed down electron acceptor molecules and returns to photosystem I) |
front 22 light independent reactions (Calvin cycle) | back 22 use products of light reactions to make sugar, in carbon fixation CO2 is used to make carbohydrates in the stroma |
front 23 What comes into dark reactions? | back 23 9 ATP, 6 NADPH, 3 CO2 |
front 24 What comes out of dark reactions? | back 24 O2, glucose, ADP, NADP+ |
front 25 What is reduced in photosynthesis? | back 25 carbon dioxide |
front 26 What is oxidized in photosynthesis? | back 26 water |
front 27 photosynthesis equation | back 27 12 H20 + 6 CO2 -sunlight-> C6H12O6 + 6O2 + 6 H2O |
front 28 oxidized | back 28 loses electrons, oxygen takes the greater ratio in the substance |
front 29 reduced | back 29 gains electrons, hydrogen has a greater ratio in the substance |
front 30 What happens to the hydrogens in the electron carriers? | back 30 they go through the Calvin cycle to become a part of glucose |
front 31 Where does carbon dioxide goes? | back 31 both the carbon and oxygen of glucose are from here |
front 32 What does the sunlight do? | back 32 its energy is stored in the chemical bonds and it initially excites water's hydrogen electrons |
front 33 When do dark reactions run? | back 33 primarily during the day, when light reactions are although they are still independent of light technically |