DO NOW

• Why do we need light?

• How does light effect our ability to live?

• What would happen if the sun burned out?

PhotosynthesisSection 8.2

Today’s Objectives

• To understand the different types of light and their wavelengths.

• To be able to explain how pigments enable us to see different colors.

• To determine the role of light and pigments in photosynthesis.

What is light?

• Energy!!!• Travels in • The distance between 2 crests is a

wavelength.

Wavelengths

• There are different wavelengths for each type of light.

Visible Light

• The light we see is called visible light.

• ROYGBIV…

Which color has…

• The shortest wavelength?

• The longest wavelength?

• What is wavelength measured in?

Why do we see COLORS?

• The color you see is the color being reflected.

• *All other colors are being absorbed.

Soooo…

• Why do plants appear to be green?

• Why is the sky blue?

We can only see Visible Light.

• From 400 – 700 nm• ROYGBV• Red has the longest wavelengths• Violet has the shortest

Pigments

• What are they?– Chlorophyll (A and B)– Carotenoids

•Xanthophylls•Carotene

Chromatography

• What is it? – A process that is able to separate out

components. A mobile phase( Gas or a liquid) moves through the stationary phase (paper)

*Video https://www.youtube.com/watch?v=ZCzgQXGz9Tg

Pigments

• Chemical compound that gives a substance it’s color

• They can absorb certain wavelengths• Pigments are everywhere (clothes,

flowers, etc.)• Ex: Chlorophyll, Carotenoids.

Why do you think pigments are necessary for photosynthesis?

Think- Pair- Share

• Use the absorption spectrum for chlorophyll…– What colors does

chlorophyll absorb?

– What colors does it reflect?

– What color does it appear to us?

Chlorophyll

• Green pigment that aids in photosynthesis.

• Found in leaves and appears green.

• Allows plant to capture light.

Think – Pair - Share

Using the absorption spectrum of carotenoids…– What colors does

carotenoid absorb?

– What colors does it reflect?

– What color does it appear to us?

Carotenoids

• Accessory Pigment that absorbs blue and green light

• Reflects: _________

• Usually hidden by chlorophyll.

Review!

• What type of light do we see?

• What is a pigment?

• What are the names of the pigments in leaves?

• Why are pigments important in photosynthesis?

Do Now– 1. What colors does this pigment

absorb?

– 2. What colors does it reflect?

– 3. What color does it appear to us?

– 4. What pigment do you think it is?