Chapter 10
Photosynthesis
Vocabulary: photosynthesis, autotroph, heterotroph, chlorophyll, mesophyll, stroma, thylakoid, light reactions, Calvin cycle, NADP+, photophosphorylation, carbon fixation, electromagnetic spectrum, wavelength, photons, spectrophotometer, absorption spectrum, action spectrum, carotenoids, photosytem, reaction-center complex, light harvesting complex, primary electron acceptor, linear electron flow, cyclic electron flow, photorespiration, bundle-sheath cells, C3 plants, C4 plants, CAM plants
Objectives:
After attending lectures and studying the chapter, the student should be able to:
1. Distinguish between autotrophic and heterotrophic modes of nutrition.
2. Distinguish between photoautotrophs and chemoautotrophs.
3. Define photosynthesis and write the general chemical equation for photosynthesis.
4. State which organisms undergo photosynthesis.
5. Distinguish between the site of photosynthesis in prokaryotic cells and in eukaryotic cells.
6. Describe the structure of the chloroplast in eukaryotic cells and describe where in the chloroplast the photosynthetic pigments are located.
7. Distinguish between radiant energy and chemical energy and relate both to the process of photosynthesis.
8. Distinguish between the electromagnetic spectrum, the visible spectrum, and an absorption spectrum.
9. State which colors of the visible spectrum are absorbed by chlorophylls and which color is reflected.
10. State which chlorophyll is required for the process of photosynthesis and is therefore found in all photosynthetic organisms.
11. State which chlorophylls are found in all plants and which other photosynthetic pigments are commonly found in plants.
12. Distinguish between the light-dependent reactions and the light-independent reactions of photosynthesis and describe the relationship between the two sets of reactions.
13. Relating to the light-dependent reactions (light reactions) of photosynthesis in eukaryotic cells (e.g. plants):
a. State the membrane and the two fluid areas in the chloroplast where the light reactions occur.
b. State and distinguish between the two different energy-storing molecules that are produced by the light reactions of photosynthesis.
c. Describe a photosystem, state the two photosystems involved in the linear (noncyclic) photophosphorylation process, and state the reaction center chlorophylls in each photosystem.
d. Explain how light energy causes the reaction center chlorophyll in a photosystem to
release an electron to a primary electron acceptor.
e. Explain why chlorophyll a is considered the main photosynthetic pigment in plants and
chlorophyll b and other pigments are considered accessory.
f. Describe where the electron given off by photosystem I goes and where the electron
given off by photosystem II goes.
g. Relate the redox reactions of an electron transport chain to the active transport of
hydrogen ions (H+) across a membrane.
h. Relate the active transport of H+ ions across a membrane to the formation of an
electrochemical gradient.
i. Relate facilitated diffusion of H+ ions through the ATP synthase protein channel to the
making of ATP.
j. State the source of a replacement electron for the one given off by the reaction center
chlorophyll P680 and the source of a replacement electron for the one given off by the
reaction center chlorophyll P700.
14. Relating to the light-independent reactions (Calvin cycle) of photosynthesis in eukaryotic cells (e.g. plants):
a. State the site of the Calvin cycle in the chloroplast.
b. State the energy-storing molecules which were produced by the light reactions and which
are used as an energy source for the Calvin cycle.
c. Show the steps of the Calvin cycle, including the major molecules involved, and explain
why the Calvin cycle is considered a cycle.
d. State the 3-carbon product of the Calvin cycle and relate it to the production of glucose.
15. Describe the major functions of glucose in photosynthetic organisms.
16. Explain the role in photosynthesis of stomata in plant leaves.
17. Distinguish the major differences between C3, C4, and CAM plants.
| 1174844074 | Photosynthesis converts light energy to the chemical energy of food | ... |  | 1 |
| 1174844075 | Chloroplasts | absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water. | 2 | |
| 1174844076 | Thylakoids | A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy. |  | 3 |
| 1174844077 | Stomata | pores on the leaf where O2 exits and CO2 enters | 4 | |
| 1174844078 | Stroma | The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water. | 5 | |
| 1174844079 | Thylakoids | A flattened, membranous sac inside a chloroplast. Thylakoids often exist in stacks called grana that are interconnected; their membranes contain molecular "machinery" used to convert light energy to chemical energy. | 6 | |
| 1174844080 | Chlorophyll | A green pigment located in membranes within the chloroplasts of plants and algae and in the membranes of certain prokaryotes. Chlorophyll a participates directly in the light reactions, which convert solar energy to chemical energy. | 7 | |
| 1174844081 | What are the two stages of photosynthesis | light dependent and light independent | 8 | |
| 1174844082 | Light Reactions | ATP, Oxygen, and NAHPH | 9 | |
| 1174844083 | Calvin cycle | H grabbed by NADH ATP H+Co2=Glucose | 10 | |
| 1174844084 | NADP | Nicotinamide adenine dinucleotide phosphate, an electron acceptor that, as NADPH, temporarily stores energized electrons produced during the light reactions. | 11 | |
| 1174844085 | 10.3 The Calvin Cycle uses the chemical energy of ATP and NADPH to reduce CO2 to sugar | ... |  | 12 |
| 1174844086 | Glyceraldehyde 3-phosphate (G3P) | A three-carbon carbohydrate that is the direct product of the Calvin cycle; it is also an intermediate in glycolysis. | 13 | |
| 1174844087 | Which of the following sequences correctly represents the flow of electrons during photosynthesis? NADPH → chlorophyll → Calvin cycle H2O → NADPH → Calvin cycle NADPH → O2 → CO2 NADPH → electron transport chain → O2 H2O → photosystem I → photosystem II | H2O → NADPH → Calvin cycle | 14 | |
| 1174844088 | Which of the following does not occur during the Calvin cycle? | release of oxygen | 15 | |
| 1174844089 | The light reactions of photosynthesis supply the Calvin cycle with | ATP and NADPH. | 16 | |
| 1174844090 | photosynthesis equation | 6CO2 + 6H2O → C6H12O6 + 6O2 Photosynthesis requires carbon dioxide and water for the production of sugar and oxygen. |  | 17 |
| 1174844091 | In which of the following organelles does photosynthesis take place? Chloroplast Mitochondrion Ribosome Central vacuole Nucleus | Chloroplast Chloroplasts use energy from light to transform carbon dioxide and water into sugar and oxygen. |  | 18 |
| 1174844092 | What two molecules are produced by the light reactions and used to power the Calvin cycle? CO2 and O2 C6H12O6 and O2 C6H12O6 and RuBP ATP and NADPH G3P and H2O | ATP and NADPH ATP and NADPH are both products of the light reactions and are used to power the Calvin cycle. |  | 19 |
| 1174844093 | What transports electrons from the light reactions to the Calvin cycle? NADH NADPH An electron transport chain FADH2 Chlorophyll | NADPH NADPH is an electron carrier that picks up electrons in the light reactions and releases them in the Calvin cycle. An electron transport chain conveys electrons from one photosystem to the other within the light reactions. | 20 | |
| 1174844094 | Where does the Calvin Cycle take place? | The Calvin cycle is a complex series of chemical reactions carried out in the stroma. | 21 |
