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 zC3-has 3 carbon chains zC4-has 4 carbon chains

C3 Plants zCannot increase increase rate of photosynthesis when light intensity is greater than 1/3-1/2 full sunlight zExamples-soybeans, cotton, potatoes, alfalfa, sugarbeets, cool season grasses

C4 Plants zCan continue to increase their rate of photosynthesis past full sunlight zExamples-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 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 6H 2 O + 6CO > C 6 H 12 O 6 + 6O 2 In English terms. Where does light fit in?

Factors affecting photosynthesis CO 2 concentration Temperature Available water Light