1. Review Q’s
1. What is the chemical equation for photosynthesis?
2. What organelle and pigment are esponsible for the
photosynthesis process?
3. Outline the absorption of red, blue and green light in
photosynthesis.
4. What are the two primary phases of the photosynthesis
process.
5. Draw and label a diagram of a dicot leaf.
3. 3.8.1
Photosynthesis is the process used by autotrophs to convert
light energy into chemical energy in the form of glucose
sugars.
6H20 + 6CO2
C6H12O6 + 6O2
In plants, chlorophyll pigments in the chloroplasts absorb
energy from light and use it to catalyze a series of reactions.
4. 3.8.2-3
Sunlight consists of many wavelengths of light, but
chlorophyll pigments power photosynthesis by absorbing
the red and blue portions of the visible light spectrum.
Recall that we are only able to see light that is reflected
(not absorbed) by an object. Therefore green plants do
not absorb green light.
5. Within the chloroplast, chlorophyll a absorbs the blue and
red portions of the spectrum while chlorophyll b absorbs
higher wavelength blues.
The green portion of the
spectrum is NOT absorbed
by any of the chlorophyll
molecules.
3.8.4
8. 3.8.5
The light-dependent stage takes place in the granum of the
chloroplast, where light energy is used to split water
(photolysis) into
H+ ions, O2,
and e-. The H+
ions are then used
to synthesis ATP via
a chemical gradient.
The O2 is released
as a byproduct.
H+ ions and ATP are used
in the ‘dark’ reaction.
9. 3.8.6
The ATP and H+ ions used to fix* CO2 molecules to
sugar molecules in the light-independent reaction.
In total, 6 CO2
are needed in
order to create
one glucose.
*Fix = taken from
the air and used
to make organic
12. Direct Measurement
Since it produces oxygen, the
rate of photosynthesis can be
determined by observing the
amount of bubbles that plants
produce over time.
You can also measure the
amount of available CO2 in an
enclosed space since it is
consumed as photosynthesis
occurs.
3.8.7
13. Indirect Measurement
Photosynthetic rate can also be
measured by measuring the
biomass of the plant over time as
well as any changes in the
inorganic matter that the plant
uses to grow.
The biomass weight can be
determined by dehydrating the
plant and measuring the dry
mass.
3.8.7
14. The following are needed for photosynthesis to
occur, so altering them will change the photosynthetic
rate.
• Chlorophyll
• Light
• Carbon Dioxide
• Water
• Suitable
temperature
These are limiting
factors. 3.8.8
15. Light Intensity
Once the chlorophyll
pigments are saturated with
light, the photosynthetic
rate can no longer increase.
Temperature
Low temperatures will
prevent the photosynthesis
from occurring. Too high
will denature the proteins
involved.
3.8.8
16. CO2 Concentration
When the reaction has
been saturated with
chlorophyll, the rate can
not increase. However, it
increases up to that point.
3.8.8
18. 3.8
3.8.1
State that photosynthesis involves the conversion of
light energy into chemical energy
3.8.2
State that light from the sun is composed of a range
of wavelengths (colors).
3.8.3
State that chlorophyll is the main photosynthetic
pigment.
3.8.4
Outline the difference in absorption of red, blue and
green light by chlorophyll.
3.8.5
State that light energy is used to produce ATP, and
to split water molecules (photolysis) to form oxygen
and hydrogen.
19. 3.8
3.8.6
State that ATP and hydrogen (derived from the
photolysis of water) are used to fix carbon dioxide to
make organic molecules.
3.8.7
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.
3.8.8
Outline the effects of temperature, light intensity and
carbon dioxide concentration on the rate of
photosynthesis.
Editor's Notes
3.8.1 – State that photosynthesis involves the conversion of light energy into chemical energy.
3.8.2 – State that light from the sun is composed of a range of wavelengths (colors).3.8.3 – State that chlorophyll is the main photosynthetic pigment.
3.8.4 – Outline the difference in absorption of red, blue and green light by chlorophyll.Students should appreciate that pigments absorb certain colours of light. The remaining colours of light are reflected. It is not necessary to mention wavelengths or the structure responsible for the absorption.
3.8.4 – Outline the difference in absorption of red, blue and green light by chlorophyll.Students should appreciate that pigments absorb certain colours of light. The remaining colours of light are reflected. It is not necessary to mention wavelengths or the structure responsible for the absorption.
3.8.5 – State that light energy is used to produce ATP, and to split water molecules (photolysis) to form oxygen and hydrogen.
3.8.5 – State that light energy is used to produce ATP, and to split water molecules (photolysis) to form oxygen and hydrogen.
3.8.6 – State that ATP and hydrogen (derived from the photolysis of water) are used to fix carbon dioxide to make organic molecules.
3.8.6 – State that ATP and hydrogen (derived from the photolysis of water) are used to fix carbon dioxide to make organic molecules.
3.8.6 – State that ATP and hydrogen (derived from the photolysis of water) are used to fix carbon dioxide to make organic molecules.
3.8.7 - Explain that the rate of photosynthesis can be measureddirectly by the production of oxygen or the uptake of carbon dioxide, or indirectly by an increase in biomass.The recall of details of specific experiments to indicate that photosynthesis has occurred or to measure the rate of photosynthesis is not expected.
3.8.7 - 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.The recall of details of specific experiments to indicate that photosynthesis has occurred or to measure the rate of photosynthesis is not expected.
3.8.8 - Outline the effects of temperature, light intensity and carbon dioxide concentration on the rate of photosynthesis.The shape of the graphs is required. The concept of limiting factors is not expected.
3.8.8 - Outline the effects of temperature, light intensity and carbon dioxide concentration on the rate of photosynthesis.The shape of the graphs is required. The concept of limiting factors is not expected.
3.8.8 - Outline the effects of temperature, light intensity and carbon dioxide concentration on the rate of photosynthesis.The shape of the graphs is required. The concept of limiting factors is not expected.
11.2.1 – State the roles of bones, ligaments, muscles, tendons and nerves in human movement.
11.2.1 – State the roles of bones, ligaments, muscles, tendons and nerves in human movement.
