Download Lights and Pigments

DO NOW
• Why do we need light?
• How does light effect our ability to live?
• What would happen if the sun burned
out?
Photosynthesis
Section 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=ZCzgQ
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?