1. Warm up 12/16 – 12/17 T-2: Plants are the original source of food molecules. If there was no light energy on Earth, could plants still make food molecules? Please explain your answer in a complete sentence(s)

2. PHOTOSYNTHESIS! Atoms in carbon dioxide and water rearrange in the cells of plants to form oxygen and glucose. What type of energy do plants need for this chemical reaction? What are the reactants? What are the products? Please take enough “atoms” to make one molecule of water and one molecule of carbon dioxide. Put the “atoms” together to make your two molecules.

3. What is your definition of photosynthesis? What makes photosynthesis a chemical reaction? What is the function of photosynthesis? Why can’t animals perform photosynthesis?

4. What are the reactants? How many molecules react? What are the products? How many molecules are produced?

5. Is the purpose of photosynthesis for plants to make food for us? Is the purpose of photosynthesis for plants to make oxygen? Why?

6. A look back at activity 1.1 In activity 1.1, you had a chance to write a scientific explanation answering the question: What happens to fat stored in the body when people lose weight? We got a variety of answers – does anyone think they can answer the question now?

7. Sample Answer – When people lose weight, the fat molecules in their bodies react with oxygen to provide energy and form carbon dioxide as a product. People lose weight when they eat fewer foods that can produce less energy than they need to survive, and those people also do activities. When this happens, the body uses stored fat to provide the energy it needs. A chemical reaction provides the cells of the body energy. In this chemical reaction, food reacts with oxygen to produce carbon dioxide. During chemical reactions, the atoms in the reactant rearrange to form the products. The atoms in the food molecules and oxygen molecules rearranged to form carbon dioxide and water to provide energy. The body systems remove the carbon dioxide from the cells. The blood carries the carbon dioxide through the circulatory system to the lungs where it is exhaled. Is there anything you would add?

8. Time to burn the oil!!!

9. December 16/17 Exit Slip: When we burned the oil in class, it was a chemical reaction. What were the reactants, and what happened to the reactants during the chemical reaction?

10. 1)What are the reactants of photosynthesis? 2)How many hydrogen atoms are in six molecules of water? 3)How many oxygen atoms are in six oxygen molecules? 4)How many carbon atoms are in a glucose molecule? 5)If oil was burned in a closed system, would the oxygen concentration in the closed system increase or decrease? 6)If oil was burned in a closed system, would the carbon dioxide concentration in the closed system increase or decrease? 7)When we burned oil in class, what were the reactants? 8)When burning food molecules, what are the products? 9) What is the name of the chemical reaction that provides energy to the cells? 10)How does the chemical reaction in question #9 compare to photosynthesis? 11)Where does photosynthesis take place? (Be specific, don’t say “in plants”) 12)Is the purpose of photosynthesis to make food for humans? (yes or no)