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Photosynthesis Study Guide
You already have a Respiration Study Guide that you should review!!!!!
Pigments
1. What are the different types of plant pigments?
Chlorophyll A and B, Xanthophyl, Carotenoids, … Accessory Pigments
2. Why are there different plant pigments? So that small amounts of green light can be absorbed and
used by the plant for photosynthesis
3. Why are plants green? (Explain by using the terms absorb and reflect.) Plants have mostly green
chlorophyll so they reflect green light back to our eye. They absorb all other colors to do photosynthesis
4. Where are the pigments contained within the chloroplast? In the thylakoid
5. What would you expect to happen if you grew a plant in green light? It would grow very slowly or die
6. Draw and label the parts of a chloroplast. Know where each step of photosynthesis occurs.
7. Why is the purpose of chromatography? To separate plant pigments to see the accessory pigments
8. How does chromatography separate pigments? Alcohol causes each pigment to rise up the filter
paper a different amount
9. How does chlorophyll contribute the first step of photosynthesis? It is used in the light reactionchlorophyll captures the photons from the sun.
Photosynthesis
10. Write out the equation for photosynthesis. What is its relationship to the equation for respiration?
6CO2 + 6H2O +sunlight  C6H12O6 + 6O2
It is the opposite of respiration.
11. What is the BIG idea of photosynthesis? Sugars are broken down to release energy
12. How did we measure the rate photosynthesis in lab? Why is this a reliable way to measure
photosynthesis? We will still do this lab on Thursday! We will count the number of Oxygen bubbles
coming off of underwater plant leaves.
13. From what step of photosynthesis do the bubbles in your lab come from? What is occurring to
cause the bubbles? Light reaction is breaking down water and releasing Oxygen as waste.
14. What is required from the environment for photosynthesis to occur? What are the products?
Water, sunlight, and carbon dioxide
Products: Glucose and oxygen
Light Reactions
15. Why are the first steps of photosynthesis named the light reactions? Light is used to excite
electrons. It will not occur without light.
16. Where do the light reactions occur? In the thylakoids
17. Describe the events in Photosystem II. (Remember, PS II then PS I)
Sunlight strikes the photosystem and breaks water molecules. The H protons and electrons are
transferred to PSI after being excited and oxygen is given off as waste.
18. Describe the events in Photosystem I.
The electrons are reexcited. NADH and FADH are produced and the electrons slide down ATP synthase
creating ATP
19. What are the reactants and products of the light reaction?
Reactants: Sunlight and water
Products: NADH, FADH, oxygen and ATP
20. What is the main job of the light reactions?
To make ATP to power the Calvin Cycle
Light Independent Reactions
21. Why is the name “dark reactions” not a good fit for the light independent reaction? The Calvin Cycle
can occur without light
22. What is the other name for the light independent reaction? Calvin Cycle
23. Describe the events of the Calvin Cycle. Carbon Dioxide is used to make glucose.
24. What extra ingredient does the Calvin Cycle need that was not needed in the light dependent
reactions? Carbon Dioxide
25. Where does the Carbon Dioxide used in the Calvin Cycle come from? The air
26. Where do the Light Independent Reactions occur? In the Stroma
27. What are the reactants and products of the Calvin Cycle?
Reactants: Carbon dioxide
Products: glucose