1. 3.8 Photosynthesis

2. 3.8.1 / Photosynthesis involves the conversion of light energy into chemical energy.

3. 3.8.1 / The chemical energy is stored in glucose or other organic compounds. / This can occur in plants, algae, and certain prokaryotes. / Photosynthesis nourishes almost all of the living world directly or indirectly. / An organism needs organic compounds for energy use and carbon skeletons by one of two major modes: autotrophic or heterotrophic nutrition. / Autotrophs are totally self-sufficient and can sustain themselves while heterotrophs obtain organic material by consuming others. / The chemical energy is stored in glucose or other organic compounds. / This can occur in plants, algae, and certain prokaryotes. / Photosynthesis nourishes almost all of the living world directly or indirectly. / An organism needs organic compounds for energy use and carbon skeletons by one of two major modes: autotrophic or heterotrophic nutrition. / Autotrophs are totally self-sufficient and can sustain themselves while heterotrophs obtain organic material by consuming others.

4. 3.8.1 / Plants and other autotrophs are the producers of the biosphere. / The biosphere is “the regions of the surface, atmosphere, and hydrosphere of the earth occupied by living organisms”(New Oxford Dictionary). / Autotrophs nourish themselves without ingesting organic molecules, however photo-autotrophs use the energy of sunlight to synthesize organic molecules from CO2 and H2O. / Plants and other autotrophs are the producers of the biosphere. / The biosphere is “the regions of the surface, atmosphere, and hydrosphere of the earth occupied by living organisms”(New Oxford Dictionary). / Autotrophs nourish themselves without ingesting organic molecules, however photo-autotrophs use the energy of sunlight to synthesize organic molecules from CO2 and H2O.

5. 3.8.1 / Chloroplasts are the sites of photosynthesis in plants. / Photosynthesis occurs in the chloroplasts, organelles containing thylakoid membranes that separate the thylakoid space form the chloroplast’s stroma. Stacks of thylakoids form grana. / Within these organelles and areas, light energy is converted into chemical energy. / In these organelles and sites, light energy is converted into chemical energy. / Chloroplasts are the sites of photosynthesis in plants. / Photosynthesis occurs in the chloroplasts, organelles containing thylakoid membranes that separate the thylakoid space form the chloroplast’s stroma. Stacks of thylakoids form grana. / Within these organelles and areas, light energy is converted into chemical energy. / In these organelles and sites, light energy is converted into chemical energy.

6. 3.8.1 / References can be seen in the Campbell book on pages: / Page 155 / Page 176 / Vocab to remember: / Autotrophs / Heterotrophs / Thylakoids / Grana / References can be seen in the Campbell book on pages: / Page 155 / Page 176 / Vocab to remember: / Autotrophs / Heterotrophs / Thylakoids / Grana

7. 3.8.2 / Light from the Sun is composed of a range of wavelengths (colors). / Sunlight can be separated into colors using a prism. Also combining the main colors or prism colors which consist of a range of wavelengths (as shown in the picture), it will portray sunlight (white light). / Light from the Sun is composed of a range of wavelengths (colors). / Sunlight can be separated into colors using a prism. Also combining the main colors or prism colors which consist of a range of wavelengths (as shown in the picture), it will portray sunlight (white light).

8. 3.8.2 / Light is a form of energy known as electromagnetic energy, or can also be known as electromagnetic radiation. / These electromagnetic energy consist of wavelengths. / Wavelengths can range from less than a nanometer to more than a kilometer. This range can be known as the electromagnetic spectrum. / 370 to 750 nm in wavelength is known as visible light, because it is detected as various colors by the human eye. / The sun radiated the full spectrum of electromagnetic energy, and the atmosphere acts like a window in that it allows visible light to pass through while screening out a substantial fraction of other radiation. / The part of the spectrum we can see (visible light) is also the radiation that drives photosynthesis. / Light is a form of energy known as electromagnetic energy, or can also be known as electromagnetic radiation. / These electromagnetic energy consist of wavelengths. / Wavelengths can range from less than a nanometer to more than a kilometer. This range can be known as the electromagnetic spectrum. / 370 to 750 nm in wavelength is known as visible light, because it is detected as various colors by the human eye. / The sun radiated the full spectrum of electromagnetic energy, and the atmosphere acts like a window in that it allows visible light to pass through while screening out a substantial fraction of other radiation. / The part of the spectrum we can see (visible light) is also the radiation that drives photosynthesis.

9. 3.8.2 / References can be seen in the Campbell book on pages: / Page 180 / Page 181 / Page 182 / Page 183 / Vocab to remember: / Sunlight (white light) / Electromagnetic energy / Wavelengths / Spectrum / References can be seen in the Campbell book on pages: / Page 180 / Page 181 / Page 182 / Page 183 / Vocab to remember: / Sunlight (white light) / Electromagnetic energy / Wavelengths / Spectrum

10. 3.8.3 / Chlorophyll is the main photosynthetic pigment.

11. 3.8.3 / The chloroplast has an intricately folded inner membrane which creates more surface area for light absorption. The folding creates things that looks like stacks of coins, which are the thylakoid, and the stack as a granum. The thylakoids provide a small space inside for the use of protons to use in ATP production. The fluid in the chloroplast (stroma) has enzymes that are used in the Calvin Cycle. / Photosynthesis consists of light-dependent and light- independent reactions. / The chloroplast has an intricately folded inner membrane which creates more surface area for light absorption. The folding creates things that looks like stacks of coins, which are the thylakoid, and the stack as a granum. The thylakoids provide a small space inside for the use of protons to use in ATP production. The fluid in the chloroplast (stroma) has enzymes that are used in the Calvin Cycle. / Photosynthesis consists of light-dependent and light- independent reactions.

12. 3.8.3 / Light-Dependent reactions. / Light hits Pohotosystem II which contains chlorophyll. This causes electrons to gain energy and just to a higher energy level. The level they are at becomes unstable, so they start to o down to a lower energy level (electron transport channel located in the thylakoids). As the electrons move from higher to lower energy levels, they release energy. The energy released is used to pump protons from the stroma to the thylakoid space. This concentrates hydrogen in the thylakoid space. This causes protons to diffuse back to the stroma down the concentration gradient. As they pass through the ATP- synthetase channels, they activate the enzyme to catalyze the phosphorilation of ADP to ATP…… / Light-Dependent reactions. / Light hits Pohotosystem II which contains chlorophyll. This causes electrons to gain energy and just to a higher energy level. The level they are at becomes unstable, so they start to o down to a lower energy level (electron transport channel located in the thylakoids). As the electrons move from higher to lower energy levels, they release energy. The energy released is used to pump protons from the stroma to the thylakoid space. This concentrates hydrogen in the thylakoid space. This causes protons to diffuse back to the stroma down the concentration gradient. As they pass through the ATP- synthetase channels, they activate the enzyme to catalyze the phosphorilation of ADP to ATP……

13. 3.8.3 / Photosystem I also absorbs light and electrons are are boosted to a higher level in energy. The energy they release is used to reduce NADP into NADPH. Then electrons lost from photosystem II are replaced by electrons from water as it splits by photolysis (splitting of water). Electrons lost from photosystem I are replaced by electrons coming down from the electron transport chain of photosystem II. This results in the formation of ATP is called chemiosmotic photophosphorylation.

14. 3.8.3 / References can be seen in the Campbell book on pages: / Page 183 / Page 184 / Page 185 / Vocab to remember: / Chlorophyll / Chloroplast / Calvin Cycle / Light-Dependent reactions / Light-Independent reactions / Photosystem I / Photosystem II / Chemiosmotic photophosphorilation / References can be seen in the Campbell book on pages: / Page 183 / Page 184 / Page 185 / Vocab to remember: / Chlorophyll / Chloroplast / Calvin Cycle / Light-Dependent reactions / Light-Independent reactions / Photosystem I / Photosystem II / Chemiosmotic photophosphorilation

15. 3.8.4 / Outline the differences in absorption of red, blue and green light by chlorophyll.

16. 3.8.4 / The absorption spectra of chloroplast pigments provide clues to the relative effectiveness of different wavelengths for driving photosynthesis, since light can perform work in chloroplasts only if it is absorbed. / The images on the previous page reveals that the spectra of a type of chlorophyll called chlorophyll a and some other pigments in the chloroplast. If we look first at the absorption spectrum of chlorophyll a, it suggests that blue and red light work the best for photosynthesis, while the green is the least effective in color. / Therefore the green is reflected, therefore making plants and such look green. / The absorption spectra of chloroplast pigments provide clues to the relative effectiveness of different wavelengths for driving photosynthesis, since light can perform work in chloroplasts only if it is absorbed. / The images on the previous page reveals that the spectra of a type of chlorophyll called chlorophyll a and some other pigments in the chloroplast. If we look first at the absorption spectrum of chlorophyll a, it suggests that blue and red light work the best for photosynthesis, while the green is the least effective in color. / Therefore the green is reflected, therefore making plants and such look green.

17. 3.8.4 / References can be seen in the Campbell book on pages: / Page 180 / Page 181 / Page 182 / Page 183 / Vocab to remember: / Chlorophyll a / Chlorophyll b / References can be seen in the Campbell book on pages: / Page 180 / Page 181 / Page 182 / Page 183 / Vocab to remember: / Chlorophyll a / Chlorophyll b

18. 3.8.5 / Light energy is used to produce ATP, and to split water molecules (photolysis) to form oxygen and hydrogen.

19. 3.8.5 / The light reactions and chemiosmosis. / Water is split by photosystems II on the side of the membrane facing the thylakoid space / As plastoquinone (Pq), a mobile carrier, transfers electrons to the cytochrome complex, protons are translocated across the membrane / A hydrogen ion is removed from the stroma when it is taken up by NADP+. The diffusion of H+ from the thylakoid space to the stroma powers the ATP synthase. These light-driven reactions store chemical energy in NADPH and ATP, which shuttle the energy to the sugar-producing Calvin cycle. / The light reactions and chemiosmosis. / Water is split by photosystems II on the side of the membrane facing the thylakoid space / As plastoquinone (Pq), a mobile carrier, transfers electrons to the cytochrome complex, protons are translocated across the membrane / A hydrogen ion is removed from the stroma when it is taken up by NADP+. The diffusion of H+ from the thylakoid space to the stroma powers the ATP synthase. These light-driven reactions store chemical energy in NADPH and ATP, which shuttle the energy to the sugar-producing Calvin cycle.

20. 3.8.5 / References can be seen in the Campbell book on pages: / Page 186 / Page 188 / Page 189 / Vocab to remember: / Chemiosmosis / Plastoquinone / References can be seen in the Campbell book on pages: / Page 186 / Page 188 / Page 189 / Vocab to remember: / Chemiosmosis / Plastoquinone

21. 3.8.6 / ATP and hydrogen (derived from the photolysis of water) are used to fix carbon dioxide to make organic molecules.

22. 3.8.6 / The Calvin cycle uses ATP and NADPH to convert CO2 to sugar. / The Calvin cycle is a metabolic pathway in the chloroplast stroma / An enzyme (rubisco) combines CO2 with ribulose bisphosphate (RuBP), a five-carbon sugar. / Using electrons from NADPH and energy from ATP, the cycle synthesizes the three-carbon sugar glyceraldehyde 3 - phosphate. Most of the G3P is reused in the cycle to reconstitute RuBP, but some exists the cycle / The ones that do are converted to glucose and other essential organic molecules. / The Calvin cycle uses ATP and NADPH to convert CO2 to sugar. / The Calvin cycle is a metabolic pathway in the chloroplast stroma / An enzyme (rubisco) combines CO2 with ribulose bisphosphate (RuBP), a five-carbon sugar. / Using electrons from NADPH and energy from ATP, the cycle synthesizes the three-carbon sugar glyceraldehyde 3 - phosphate. Most of the G3P is reused in the cycle to reconstitute RuBP, but some exists the cycle / The ones that do are converted to glucose and other essential organic molecules.

23. 3.8.6 / References can be seen in the Campbell book on pages: / Page 189 / Page 190 / Page 191 / Page 192 / Vocab to remember: / ATP / NADP and NADPH / RuBP / Rubisco / References can be seen in the Campbell book on pages: / Page 189 / Page 190 / Page 191 / Page 192 / Vocab to remember: / ATP / NADP and NADPH / RuBP / Rubisco