What Should I Know About Photosynthesis s1

WHAT SHOULD I KNOW ABOUT PHOTOSYNTHESIS? Name______

1. What is an autotroph? Give examples: An organism that makes its own food. Ex. Plants, some Protists, some Eubacteria, and some Archaebacteria

2. What is a Heterotroph? Give examples. An organism that must consume other organisms for energy. Ex. Animals, Fungi, some Protists, some Eubacteria, and some Archaebacteria.

3. In which organelle (in plants) does photosynthesis take place? ____Chloroplast______

4. Which molecule is used by living things to store and transfer energy? ____ATP_____

5. Which food molecule do the living things get the energy from? ____Glucose______

6. Photosynthesis requires light, water, carbon dioxide, and ____I will accept chlorophyll, chloroplasts, ATP, Nutrients, Leaves______.

7. Write out the chemical equation for photosynthesis below: 6CO2 + 6H2O + Sunlight  C6H12O6 + 6O2

8. Which molecules are the inputs or reactants? 6CO2 + 6H2O (Sunlight is not a molecule)

9. Which molecules are the outputs or products? C6H12O6 + 6O2

10. What chemical form of energy is made during the light dependent reactions? ___ATP/NADPH____

11. What are some of the factors that might influence how fast or slow photosynthesis takes place? Temperature, Amount of Light, Amount of water, Amount of Carbon dioxide.

12. Where do plants get the CO2 that they need for photosynthesis? From the atmosphere and from animals breathing it out.

13. What is the main pigment used by green plants to absorb energy? ______Chlorophyll______

14. Which wavelengths of light are best absorbed by the main pigment in plants? All except for Green

15. Which wavelengths of light are reflected? ______Green______

16. Why do plants have these other pigments besides chlorophyll? So they can still photosynthesize during fall when chlorophyll is being reabsorbed. This way they do not lose out on energy.

17. Why do plants look green? A They have chlorophyll which reflects green light and our eyes pick up and perceive the color to be green. B 18. Label the parts of a chloroplast and tell where the reactions for photosynthesis happen. A= ___Thylakoid Membranes_____ B= ___Stroma____ 19. Place in chloroplast where light dependent reactions happen = ______thylakoids______

20. Place in chloroplast where Calvin Cycle or Light Independent Reactions occurs = ___Stroma______

21. What things are the inputs or reactants for the light dependent reactions? Water and Sunlight

22. What things are the outputs or products for the light dependent reactions? Oxygen, ATP and NADPH

23. What things are the inputs or reactants for the light independent reactions? Carbon Dioxide, ATP and NADPH

24. What things are the outputs or products for the light independent reactions? Glucose

25. Where does the carbon and oxygen in glucose ultimately come from? From Carbon Dioxide or CO2

26. Where does the hydrogen in glucose ultimately come from? From the water or H2O

27. A student exposed four plants to different colors of light. He exposed two plants to only red light and two plants to only green light. Which plants should grow better? Why? The only ones that will do well are the ones in red light because plants reflect green light. If they reflect green light, then it will not provide the energy to drive the light dependent reactions. They will die if they are exposed to the green light long-term. The red light will at least provide some energy to drive the LDRs.

28. What is the difference between xylem and phloem tissues? Xylem is a tissue designed to transport only water in plants from the roots, whereas phloem is a tissue designed to transport glucose (food) around the plant.

29. What are stomata and what do they do? Stomata are the small openings on the underside of the leaf where gas exchange occurs. Oxygen will exit during the light dependent reactions and carbon dioxide will enter during the light independent reactions. There are two small cells that regulate how “open” the stomata are and they are called guard cells.

30. What is the name of the cells that regulate the stomatal openings? _____guard cells______

31. (A good short answer question here!) Why is important for plants to have both a daily cycle of both daylight and night? Be specific and explain. Plants go through two stages of photosynthesis: the light dependent reactions and the light independent reactions. The light dependent reactions can only take place when there is active sunlight, whereas the light independent reactions can only take place when there is no sunlight. Oxygen leaves the stomata during the day and carbon dioxide enters the stomata during the evening. If oxygen and carbon dioxide enter and exit at the same time, it would not be very efficient and less glucose would probably be made overall.