Download Photosynthesis: Lock and Key of Earth

Photosynthesis
Lock and Key of Earth
Topic #2015
Matt Jakubik
Why Learn About Photosynthesis?
• Photosynthesis is the
most important chemical
reaction on earth.
What is it?
• Process plants use to
convert carbon
dioxide and water
into sugar and
oxygen
Picture taken from Life: The Science of Biology, 4th edition, by Sinauer Associates and WH Freeman
Plants as Autotrophs
• Autotrophs: Make their own energy
• Heterotrophs: Get energy from other living
organisms
Light
• How do plants make their energy?
• Is all light the same?
• The more the better?
• What properties does light have?
Wavelength
•
is the symbol
for wavelength
• Energy of light is
inversely related to
the wave length
Picture taken from Life: The Science of Biology, 4th edition, by Sinauer Associates and WH Freeman
Light quality
• Spectrums
• Visible light
• Plants mainly use Red
and Blue
• Why are plants
green?
Picture taken from Life: The Science of Biology, 4th edition, by Sinauer Associates and WH Freeman
Light Quantity
• Measured in micromoles/m²
• Light quantity is the amount of light that
hits a surface
• What variables can you think of that
would affect light quantity?
Duration
• Generally referred to as daylength in the
field.
• Affects flowering, bulbset, tuberset,
germination, budset… etc.
• What are some benefits of greenhouse
lighting? (think back to what we
discussed in the last slide)
Two Types of Photosynthesis
C3-has 3 carbon chains
C4-has 4 carbon chains
C3 Plants
Cannot increase increase rate of
photosynthesis when light intensity is
greater than 1/3-1/2 full sunlight
Examples-soybeans, cotton, potatoes,
alfalfa, sugarbeets, cool season grasses
C4 Plants
Can continue to increase their rate of
photosynthesis past full sunlight
Examples-corn, sorghum, sugarcane, and
warm season grasses
So Where Does
the Light Go to
Do It’s Thing?
Plant Cell Structure
• The following are
important to know
•
•
•
•
•
Xylem
Phloem
Guard cell
Stoma
Chloroplasts
Picture taken from Life: The Science of Biology, 4th edition, by Sinauer Associates and WH Freeman
Plant Organelle Function
•
•
•
•
Xylem
Phloem
Guard Cell
Stomata
Stomata
Picture taken from Life: The Science of Biology, 4th edition, by Sinauer Associates and WH Freeman
The All Important Chloroplast
• What is the
chloroplast?
• What is chlorophyll?
• Thylakoids?
Picture taken from Life: The Science of Biology, 4th edition, by Sinauer Associates and WH Freeman
Formula for photosynthesis
6H2O + 6CO2 ----------> C6H12O6+ 6O2
In English terms.
Where does light fit in?
Factors affecting photosynthesis
•
•
•
•
CO2 concentration
Temperature
Available water
Light