Photosynthesis Key
Read these questions first. Then put away the question sheet and completely read “Making
Carbon Compounds” pp 330 –333. Then use your book to answer the questions in your own
words in your science notebooks using IQIA. Do not use “it” or “they” as subjects.
1. What are the three major events in Photosynthesis? Absorption of light, conversion of light energy into
chemical energy, storage of energy in sugars.
2. What are the two distinct and interdependent sets of reactions? Light dependent and independent
reactions.
3. Light dependent reactions require two factors from outside the plant. What are they? Sunlight and
water.
4. Where in the plant does photosynthesis occur? Chloroplast.
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Light energy is converted to what molecule? Adenosine triphosphate. What is its short name? ATP
Which macromolecule are enzymes made from? Proteins
What is the function of an enzyme? To speed up any chemical reaction, in this case it is photosynthesis
Draw a labeled diagram of the splitting of water.
H+ H+ H+ H+ O-O
9. What is the byproduct from the light–dependent reaction? O2
10. What does light independent mean? Light not required
11. What molecule is required in the light independent reaction that is a product of the light dependent
reactions? ATP
12. When does the light independent reaction occur? Simultaneously with the light dependent.
13. What other name is the light independent cycle called? Calvin Cycle
14. What kind of energy does sugar provide? Chemical Energy
15. Where does a plant get carbon atoms to build sugar molecules? Atmospheric carbon dioxide.
16. What does carbon fixation mean? (in simple terms) The carbon is formed into a molecule or is forced
“fixed” into am molecule
17. Write the overall photosynthesis reaction symbols and words in your lab book.
18. Why does a plant produce sugar? For food; plants are autotrophs or producers
19. List the molecules that a plant can convert the carbon chains into. Sucrose, starch and cellulose
20. How is sucrose transported through the plant? Through veins in the plant.
21. What can the starch be turned into? Lipids, proteins, and other organic molecules.
22. Why is it so easy to turn starch into these other molecules? Starches (carbohydrates), like the others are
made of CHON and these elements are then transferred into the other 3 organic molecules (lipids,
proteins and nucleic acids)