2.9 PHOTOSYNTHESIS Practice Question
Address the following Assessment Statements
 State that photosynthesis involves the conversion of light energy into chemical energy.
 Describe the Sunlight with respects to A range of wavelengths (colours).
 Identify the main photosynthetic pigment.
 Outline the differences in absorption of red, blue and green light by chlorophyll.
 Identify four products/ molecules photolysis stage of photosynthesis
 Identify the forms/ molecules of chemical energy that are used to fix carbon dioxide to make organic molecules.
 Explain that the rate of photosynthesis can be measured directly by the production of oxygen or the uptake of
carbon dioxide, or indirectly by an increase in biomass.
 Outline the effects of temperature, light intensity and carbon dioxide concentration on the rate of
photosynthesis.
The shape of the graphs are required.
 Explain methods by which the rate of photosynthesis can be measured, including conditions that affect the rate
. (HINT: you can discuss specific experimental designs)
 Explain why carbon dioxide concentration is a limiting factor of photosynthesis
 Explain the effect of light intensity and temperature on the rate of photosynthesis.
 Explain methods that can be used to measure the rate of photosynthesis.
 Draw and label the action spectrum/ absorption spectrum of photosynthesis
 Explain how you can separate the photosynthetic pigments using chromatography
Practice Questions: Using PowerPoints to fill in the answers below.
1. Define photosynthesis
The conversion of ________________________ into _______________________ in plants. (1 p. 65)
2. Write a word equation and balanced symbol equation for the process of photosynthesis.
Word:
Symbol
3. Glucose is a product of photosynthesis. It can be used directly in respiration, stored as starch or converted to
glucose.
a. Distinguish between the functions of starch and cellulose.
Starch:
Cellulose:
b. Identify and outline the process of condensation to form a disaccharide.
c. Explain why a plant which is left in the dark for a long period of time will test negative for starch.
4. Light from the Sun is composed of a range of wavelengths (colours).
a. Outline the properties of these wavelengths of light:
Wavelength
(nm)
10-400
Name
Ultraviol
et
Infra-red
Photosynthesi
s?
No
No
Visible?
No
Energy
Very
High
Low
Frequency
Very
High
Low
400-500
Yes
500-650
Yes
0.81000µm
700-800
Yes
No
5. State the name of the photosynthetic pigment and its location in green plants.
Name: ________________________
Location: ______________________________
6. Distinguish between action and absorption spectra for photosynthesis.
Action:
Absorption:
7. Use the spreadsheet here to produce action spectrum for photosynthesis and absorption spectrum for
chlorophyll: https://www.box.net/shared/cs6jvzv8n4
8. In the space
below, draw a
graph showing the
action and
absorption spectra
for chlorophyll.
Annotate the
diagram to show
why leaves appear
green.
Leaves appear green because…
Summarise the two main stages of photosynthesis:
Input
Outcome
Light energy is used to…
Lightdependent
reactions
Light
independe
nt
reactions
9. Define rate, with regard to reactions.
10. Explain how the rate of photosynthesis can be measured directly and indirectly.
Direct Measurement 1
Product:
Explanation:
Direct Measurement 2
Product:
Explanation:
Indirect Measurement
Explanation:
Outcome:
11. Outline the effects of the following variables on the rate of photosynthesis.
Sketch and annotate a graph for each one.
Light intensity
Note: light intensity is not the same as wavelength or frequency. Light intensity refers to the amount of
light of a given wavelength which is available to the plant. Light intensity is high at the equator,
in the summer or at midday.
Temperature
Carbon dioxide concentration