Light & Photosynthesis
Floral Careers Plant Propagation
The Electromagnetic Spectrum
Colors of Light that Plants Use
• Plants absorb red light.
• Plants absorb blue light.
• Plants don’t absorb green light, they
reflect green light.
Sources of Light
• Sun
• Artificial Lights
• Incandescent bulbs
• Fluorescent bulbs
• Specialized lights for plant growth
HID Lights in the Kirkwood Greenhouse
Where in Plants is Light Being
Absorbed?
• Leaves.
• Sometimes by the stems.
• Specifically light is absorbed by a
chemical compound called
chlorophyll.
Chlorophyll
• A green-colored chemical pigment
found in the chloroplasts of plant
cells.
Leaf Cross-sectional View Showing
Plant Cells with Chloroplasts
Does This Plant Have
Chlorophyll?
YES!
• Chlorophyll is still present in the
leaves.
• It’s presence is masked by the more
dominant red and purple pigments.
Autotrophs
• Living organisms capable of
manufacturing their own food.
• Plants are autotrophs.
Photosynthesis
• Inputs:
•
•
•
•
Light
Water
Carbon dioxide
Chlorophyll
Photosynthesis
• Outputs
• Oxygen
• Sugar (glucose) = Food
• See, plants really are autotrophs!
Paul’s Circle of Life
The End