Guided notes covering material from Topic 2.9 of the updated IB Biology syllabus for 2016 exams. Notes sequence and prompts are based on the Oxford IB Biology textbook by Allott and Mindorff.

1. IB Biology Chapter 2 Notes: Photosynthesis (2.9) NAME:
Word Definition
Pigment A molecule that absorbs light of a specific wavelength
Electromagnetic
spectrum
All the possible wavelengths that light/radiation can have. These are waves of
photons that have different wavelengths and frequencies.
Chlorophyll The main pigment in photosynthesis
Wavelengths The different “colors” or types of photons that exist
Absorbance The wavelengths that are taken up by a pigment
Action spectrum The wavelengths of light that are actively used for photosynthesis
Reflection The wavelengths that are unable to be absorbed by a pigment. They bounce of the
object and are “seen.”
Transmittance The wavelengths that are unable to be absorbed by a pigment but pass through the
object.
Photolysis The splitting of water using the power of the sun (light absorption)
Chloroplast The organelle in plant cells where photosynthesis occurs.
Chromatography Process used to separate different pigments.

2. 2.9.1 Photosynthesis is the
production of carbon
compounds in cells using
light energy.
2.9.9 Separation of
photosynthetic pigments by
chromatography.
2.9.2 Visible light has a
range of wavelengths with
violet the shortest
wavelength and red the
longest.
2.9.3 Chlorophyll absorbs
red and blue light most
effectively and reflects green
light more than other colors.
2.9.10 Draw an absorption
spectrumfor chlorophyll and
an action spectrumfor
photosynthesis.
2.9.4 Oxygen is produced in
photosynthesis from
photolysis of water.
Photosynthesis:
What is the energy conversion that occurs in photosynthesis?
What is chromatography used for?
Describe how chromatography works:
List examples of pigment molecules found in chloroplasts:
Examples of high-energy, shorter-wavelength light:
Examples of low-energy, longer-wavelength light:
Wavelengths ofvisible light:
Blue =
Green =
Red =
Colors absorbed by chlorophyll:
Colors reflected by chlorophyll:
Why do most plants appear green?
Outline what occurs in photolysis:

3. 2.9.7 Changes to the Earth’s
atmosphere, oceans,and
rock deposition due to
photosynthesis.
2.9.5 Energy is needed to
produce carbohydrates and
other carbon compounds
from carbon dioxide.
2.9.6 Temperature, light
intensity, and carbon dioxide
concentration are possible
limiting factors on the rate of
photosynthesis.
2.9.8 Design experiments to
investigate limiting factors
on photosynthesis.
When did the first photosynthetic organisms emerge?
What was the Great Oxidation Event?
How did photosynthesis contribute to Earth’s first glaciation?
What change in atmospheric oxygen occurred around 700-600 million years ago?
Describe how carbohydrates are produced in photosynthesis:
Outline limiting factors on photosynthesis:
Answer the questions based on the experiment described on pages 137-138:
What is the independent variable in the experiment?
What is the dependent variable in the experiment?
What are some control variables in the experiment?
Describe how you could modify this setup to test a different limiting factor on photosynthesis: