2. Photosynthesis Notes Essential Questions: 1.How do our cells determine who we are? 2.How do living things obtain and use energy?

3. 1. What is the difference between autotrophic organisms and heterotrophic? Give an example of each. Autotrophs can make their own food, heterotrophs have to eat other living things to get energy. Autotrophs: plants heterotrophs: animals

4. 2. What is adenosine triphosphate (ATP)? Why is it important to living things? Molecule that cells use to store and release energy. It’s the form of energy cells get from breaking down sugar for energy.

5. 3. What is the main difference between ATP (adenosine triphosphate) and ADP (adenosine diphosphate)? ATP has 3 phosphate groups, ADP only has 2 “tri” = 3, “di” = 2

6. 4. Use the space below to draw simplified diagrams of an ATP molecule and an ADP molecule as shown on p. 203. Explain how living things use these two molecules to store or release energy. Energy released by breaking bond between 2 nd and 3 rd phosphate group of ATP, making it ADP. Energy stored by adding 3 rd phosphate to ADP, making it ATP.

7. 5. With respect to energy, how are ATP and glucose similar? How are they different? Both are molecules that cells use for energy. Glucose has more energy, but harder for cells to actually use. Like trying to use a $100 bill in a vending machine. ATP has less energy, but easier for cells to use. Like $1 bill.

8. 6. What is photosynthesis and why is it important to life on Earth? The way plants use light energy to make food in the form of sugar (glucose). Photosynthesis at beginning of almost every food chain on Earth.

10. 7. How are each of the following related to photosynthesis? Glucose – Chloroplasts – Chlorophyll - the sugar made in photosynthesis the organelle in plant cells where photosynthesis happens. the green pigment in chloroplasts that absorbs light needed for photosynthesis.

11. 8. Write the chemical equation for photosynthesis using symbols and words. What are the reactants? What are the products? 6CO 2 + 6H 2 O + (energy) C 6 H 12 O 6 + 6O 2 Carbon dioxide water light Glucose (sugar) oxygen reactants products

12. 9. Why are carbon dioxide and water needed for photosynthesis? 6CO 2 + 6H 2 O + energy C 6 H 12 O 6 + 6O 2 Carbon dioxide waterlight Glucose (sugar) oxygen They provide the carbon, hydrogen, and oxygen atoms needed to make glucose. CO 2 and H 2 0 molecules are taken apart, and their atoms are re- assembled into glucose and oxygen.

13. 10. Why are light and chlorophyll needed for photosynthesis? 6CO 2 + 6H 2 O + energy C 6 H 12 O 6 + 6O 2 Carbon dioxide waterlight Glucose (sugar) oxygen Light provides the energy needed to take apart CO 2 and H 2 0 molecules. Chlorophyll enables plant cells to absorb light energy for photosynthesis.

14. 11. How well would a plant grow under pure yellow light? Use the graph on p. 207 to explain your answer. Probably not well. Chlorophyll a & b absorb blue and red light very well. Neither absorbs green or yellow light well (they reflect instead).

15. Photosynthesis & Food http://ed.ted.com/lessons/the-simple-but-fascinating- story-of-photosynthesis-and-food-amanda-ooten 1.What did you learn about photosynthesis? 2.What questions do you have about it?

16. Exit Slip What did you learn today about photosynthesis? What questions do you have about it? Your name

17. Questions?

18. On scratch paper….. Question: How does light exposure affect starch levels in plants? Starch molecules are made up of _______ molecules joined together. sugar

19. On scratch paper….. Question: How does light exposure affect starch levels in plants? Starch molecules are made up of _______ molecules joined together. sugar Benedict’s solution: turns blue-green-yellow-orange-red in presence of sugar. Iodine: turns yellow – blue/gray in presence of starch.