Download Study Guide – Photosynthesis Quiz ANSWER KEY Define the

Study Guide – Photosynthesis Quiz ANSWER KEY
1. Define the following terms:
a. Autotroph: an organism that makes their own food from inorganic material
b. Heterotroph: an organism that needs to eat food in order to get energy
c. Stroma: area in the chloroplast where the Calvin cycle takes place
d. Thylakoid: area in the chloroplast where the light reactions take place
e. Grana: stack of thylakoids
f.
Chloroplast: organelle only found in plant cells
2. What is the reaction equation for photosynthesis and where do they originate from?
6 CO2 + 6 H2O + light energy  C6H12O6 + 6 O2. The CO2 comes from organisms
breathing in the atomosphere. The H2O comes from rain. The light energy comes from
the sun. The C6H12O6 is the product of the Calvin cycle. The O2 is the byproduct of the
light reactions.
3. Why is it that we see leaves as a green color?
Chlorophyll can absorb all colors of light except for green. Green light is reflected
from the chlorophyll, which is the color we see.
4. Where do the following reactions take place in the chloroplast?
a. Photosystem I: Thylakoid membrane
b. Photosystem II: Thylakoid membrane
c. Calvin cycle: Stroma of the chloroplast
5. What are the end products for the following reactions?
a. Photosystem I: NADPH
b. Photosystem II: ATP & O2
c. Calvin cycle: Glucose
6. List the steps in the Light Dependent Reactions.
a. Water is split creating O2, H+, and e-. The e- of this reaction move to a reaction
center.
b.
The reaction center absorbs light, excites the e- and the e- moves to the eacceptor.
c.
The e- moves from the e- acceptor to the ETC and then ATP can be made.
d.
The e- from the ETC is moved to the reaction center of Photosystem I.
e. The reaction center absorbs light, excites the e- and the e- moves to the eacceptor.
f.
The e- moves from the e- acceptor to the ETC and NADPH is made.
7. List the steps in the Light Independent Reactions.
a.
A CO2 molecule binds to a 5-carbon molecule RuBP with help of the enzyme
rubisco. This molecule breaks into two 3-PGA molecules.
b.
The 3-PGA molecules are unstable and use energy from ATP and a H from
NADPH to become G3P.
c.
One G3P molecule leaves the Calvin cycle to become a glucose molecule.
d. The remaining G3P molecules go back into the cycle and use energy from ATP
to become RuBP and start the system over again.
8. What are the 3 factors that affect the rate of Photosynthesis?
The three factors that affect the rate of photosynthesis are temperature, light
intensity, and amount of CO2.
9. How are C3, C4, and CAM plants different from each other?
C3 and C4 plants both usually have their stomata open during the day, whereas CAM
plants only have their stomata open at night.
10. What is the reason why leaves change color in the fall?
As the fall season approaches, there are less light hours in the day, which results in
lower levels of chlorophyll being produced. In this case, the chlorophyll can no longer
mask the carotenoid pigment, which shows through giving the yellow and orange
coloration.
11. Complete the following graph.
C
O
2
Rubi
sco
RuBP
3PG
A
A
A D
T P
P
A
D
P
A
T
P
NAD
NADPH
P+
G
3
P
G3
P
Gluc
ose