Objective: You will be able to write the equation of photosynthesis.

Do Now:• Read “Autotrophs and heterotrophs” on p. 201• Differentiate between autotrophs and

heterotrophs

Photosynthesis Equation

6CO2 + 6H2O C6H12O6 + 6O2

Carbon + Water Glucose + Oxygen

Dioxide

Bromothymol

• Used to test for the presence of carbon dioxide (CO2)

• If CO2 is present it is a yellow color

• If CO2 is NOT present it is a blue color

Objective: You will be able to identify and give the function of the parts of a leaf.

Do Now:• Read “Light and pigments” on p. 207• List the FOUR things that plants need to have

for photosynthesis

Vein

Leaf cross section

Mesophyll

CO2 O2Stomata

Chloroplasts: The Sites of Photosynthesis

Chloroplast

Mesophyll

5 µm

Outermembrane

Intermembranespace

Innermembrane

Thylakoidspace

Thylakoid

GranumStroma

1 µm

Activity

• View a leaf slide under medium power

• Locate the stomata– They should be on the bottom, if they are on

top you slide is upside down.

• Draw a small region of the leaf

• Label the various parts of a leaf that we learned about

Objective: You will be able to identify experimental variables

Do Now:• Read “Setting up a controlled experiment” on p. 9• Differentiate between manipulated and

responding variables

Controlled Experiments

• Have an independent variable– The “thing” that you are changing

• Have a dependent variable– The “thing” that is affected when you change

the independent variable

• Manipulated variable?

• Responding variable?

Example

• Which color light works best for photosynthesis?

• What is the:– Independent (manipulated) variable?– Dependent (responding) variable?

Controlled experiments

• Also use one setup known as the control group

• A control group is where the manipulated variable is removed

• You can think of the control group as being used for comparison

Examples of controls

• What color light is best for photosynthesis?– Control is one that does not have a particular

color of light.

• Will plants grow more if fertilizer is added?– Control is the setup that does not get the

fertilizer

You try

• What affect does the intensity of light have on photosynthesis?

• Using a partner come up with the:– Manipulated variable– Responding variable– Control group

Problems1. Will plants carry out more photosynthesis

if they are given more CO2?2. Will plants grow more if they are exposed

to “dark light”?3. Can plants produce more oxygen if you

talk to them?4. What type of music will cause plants to

release more oxygen?5. What effect does temperature have on

the growth of plants?

Objective: You will be able to explain how plants can absorb light for photosynthesis.

Do Now:• Read “Light and pigments” again on p. 207

• What colors of light are absorbed by a plant?

Chloroplast

Mesophyll

5 µm

Outermembrane

Intermembranespace

Innermembrane

Thylakoidspace

Thylakoid

GranumStroma

1 µm

Gammarays X-rays UV Infrared

Micro-waves

Radiowaves

10–5 nm 10–3 nm 1 nm 103 nm 106 nm1 m

106 nm 103 m

380 450 500 550 600 650 700 750 nm

Visible light

Shorter wavelength

Higher energy

Longer wavelength

Lower energyFigure 10.6

Light

ReflectedLight

Chloroplast

Absorbedlight

Granum

Transmittedlight

Figure 10.7