Essential Biology 03.8 & 8.2/C4 Photosynthesis
Resources: http://sciencevideos.wordpress.com/bis-ib-diploma-programme-biology/03-makingatp/photosynthesis-inc-ahl-82-and-c4/
1. Define photosynthesis
2. Write a word equation and balanced symbol equation for the process of photosynthesis.
3. Summarise the two main stages of photosynthesis:
Input
Outcome
Light-dependent reactions
Light independent reactions
4. Glucose is a product of photosynthesis. It can be used directly, stored as starch or used to make
cell walls (as cellulose).
a. Which process results in the formation of polysaccharides from monosaccharides?
b. Outline the process below.
c. What are the steps in testing a leaf for the presence of starch?
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 03.8 & 8.2/C4 Photosynthesis
d. Explain why a starch test will be negative if a green plant Is left in the dark for a long period
of time.
5. Light from the Sun is composed of a range of wavelengths (colours).
a. Distinguish between frequency and wavelength in terms of electromagnetic radiation.
b. Between which wavelengths is light visible to the human eye?
c. Match the ranges of wavelengths below with their colours.
i. 400-500nm =
ii. 500-650nm =
iii. 700-800nm =
6. What is chlorophyll? In which organelle can it be found?
7. Distinguish between action and absorption spectra for photosynthesis.
8. Use the spreadsheet here to produce action spectrum for photosynthesis and absorption
spectrum for chlorophyll: https://www.box.net/shared/cs6jvzv8n4
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 03.8 & 8.2/C4 Photosynthesis
9. In the space below, draw a graph showing the action and absorption spectra for chlorophyll.
Annotate the diagram to show why leaves appear green.
10. Outline the reasons for some plants having leaves that are not green.
11. In the space below, draw and label a diagram of a chloroplast, as seen under a TEM.
Include thylakoid membranes and thylakoid spaces, stroma, granum, chloroplast
envelope and a scale bar. Annotate the diagram with the function of each component and the
way it is adapted to increased efficiency.
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 03.8 & 8.2/C4 Photosynthesis
12. Photosynthesis consists of two stages: light dependent and light independent reactions.
a. Define photolysis
b. Define photophosphorylation
c. Define carbon fixation
13. Explain what happens to an electron when it is excited by photons of light.
14. Annotate the diagram below to explain the light-dependent reactions of photosynthesis.
Include photolysis, photophosphorylation (and chemiosmosis), movement of electrons,
generation of a H+ gradient using a proton pump, reduction of NADP+ by ferredoxin.
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 03.8 & 8.2/C4 Photosynthesis
15. Which two products of the light-dependent reactions are carried through to the lightindependent reactions?
16. What is the name of the 5-carbon compound present in the Calvin cycle?
17. Define carboxylation and decarboxylation.
18. In the space below, draw a diagram to explain the cycle of reactions that occur in the lightindependent stages of photosynthesis. Include carboxylation of RuBP to glycerate-3-phosphate
by rubisco, reduction to triose phosphate, formation of glucose phosphate and reformation of
RuBP.
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 03.8 & 8.2/C4 Photosynthesis
19. Describe three ways (two direct and one indirect) in which the rate of photosynthesis can be
measured.
Direct 1:
Direct 2:
Indirect:
20. In the space below, draw a set of axes and a curve explaining how light intensity can affect the
rate of photosynthesis of a green plant.
21. In the space below, draw a set of axes and a curve explaining how carbon dioxide
concentration can affect the rate of photosynthesis of a green plant.
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 03.8 & 8.2/C4 Photosynthesis
22. In the space below, draw a set of axes and a curve explaining how temperature can affect the
rate of photosynthesis of a green plant.
A limiting factor is the one factor which is in shortest supply or is preventing the rate of a reaction from
increasing. If this factor were increased, rate of reaction would increase until another plateau was
reached (a different factor is then limiting).
23. Explain how the following factors can limit the rate of photosynthesis of green plants:
(give reasons specific to the reactions of photosynthesis)
Factor
Which stages of photosynthesis are limited and how?
Carbon dioxide concentration
Low CO2 means less carbon can be fixed from the atmosphere in the
Calvin cycle. Output of glucose is reduced and RuBP builds up.
Light intensity
Temperature
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com
Essential Biology 03.8 & 8.2/C4 Photosynthesis
24. Using the graph below, deduce, with reasons, the most important limiting factor in the
rate of photosynthesis of this green plant.
25. Compare photosynthesis and respiration.
Take time to think about all the connections – reactions, structures, products and processes.
Stephen Taylor
Bandung International School
http://sciencevideos.wordpress.com