Why study photosynthesis?. Environment Source of earth’s oxygen Uses carbon dioxide to prevent...
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Transcript of Why study photosynthesis?. Environment Source of earth’s oxygen Uses carbon dioxide to prevent...
Why study photosynthesis?
Environment
• Source of earth’s oxygen
• Uses carbon dioxide to prevent greenhouse gases
Agriculture• Food
• Sugar cane most efficient plant
Energy Production• Ethanol and fuels
Electronics
• Solar power• Light-based computer
chips
Medicine/Health Care
• Natural sunscreens• Cures for disease• Skin care
Fiber/Materials
• Clothes• Construction• Paper, wood
What is Photosynthesis
(Sunlight and chlorophyll)
C02 + H20------------------- C6H1206 + 02
Carbon dioxide + water makes glucose + oxygen
Where does it take place?
Chloroplasts in leaves
Assignment
• Fold a piece of paper into thirds
• Draw and color a LEAF (See Figure 23-18, pg. 596). Label the veins.
• Draw and color the LEAF CROSS SECTION on pg. 596.
• Label the spongy mesophyll, guard cells, cuticle, upper epidermis, palisade mesophyll, xylem, phloem, vein, lower epidermis, stoma.
• Draw and color the CHLOROPLAST on pg. 208.
• Label the stroma, granum, thylakoids.
• It should look like this:
Leaf Cross-section
chloroplast
Leaf cross-section“Pathway of Photosynthesis”
C02 + H20------------------- C6H1206 + 02
Cuticle-waterproof, waxy coating; protects leaf from water loss
cuticle
Epidermis- cube shaped cells; outermost layer; upper and lower
LIGHT ENTERS HERE
Upper epidermis
Lower epidermis
Mesophyll includes:
Palisade layer- tall columnar shaped cells: CONTAIN CHLOROPLASTS
Palisade layer
Mesophyll includes:Spongy layer – cells arranged with air spaces – OXYGEN AND C02 ENTER
AND LEAVE HERE
Spongy Mesophyll
Vascular bundle-veinXylem-WATER moves UP to
leaves FROM ROOT
Xylem
Vascular bundlePhloem-FOOD moves DOWN to
ROOTS
Phloem
Stomata- opening to allow water and GAS exchange
stomata
Guard Cells-regulates opening of stomata according to water
pressure
Guard cells