Refresher Question What is a leaf’s main function? Make food! PHOTOSYNTHESIS

Refresher Question What plant structure do you see here: ROOT

Refresher Question What is the green pigment that captures light called? Chlorophyll

Refresher Question What is the cell organelle that contains chlorophyll called? Chloroplast

Plant Video National Geographic Video

Photosynthesis Plants use energy from sunlight to make food from carbon dioxide and water. 6CO2 + 6H2O Sunlight C 6 H12O 6 + 6O2 Chlorophyll Green Color Part of the Chloroplasts Captures sunlight

Plant Puzzler What is the energy source that drives photosynthesis? SUN

Sugar (Glucose) C 6 H12O 6  6 Carbon, 12 Hydrogen, 6 Oxygen Glucose is stored energy plants use for food Made from CO2, H2O, Sunlight and chlorophyll

Plant Puzzler The kind of food produced directly from photosynthesis is __________? Sugar = Glucose = C 6 H12O 6

Gas Exchange in Leaves Cuticle: waxy covering that protects plant How does gas “break through” that tough barrier? Stoma! (plural= stomata) an opening in a leaf or stem that allows gas exchange Each stoma has 2 Guard Cells Guard Cells open or close stoma Closed stoma = no gas exchange Open stoma = gas exchange Carbon Dioxide (CO2), Oxygen (O2), and Water Vapor (H2O)

Plant Puzzler An opening in a plant that allows for gas exchange is called a __________? What gases are transported through the stoma? Stoma CO2, O2, H2O

Question #1 Put a plant under a dark box. Is this plant undergoing photosynthesis? Why or why not?

Question #2 Describe what you think will happen to the life seen here (and on Earth), after a meteor blackened the sky so that no sun could shine through?

Question #3 Are the leaves you see here undergoing photosynthesis? Why or why not? Pretend that the branch is still attached to the living tree.

Question #4 If you and a large tree were locked in an airtight compartment, with plenty of food, water, and nutrients, could you survive? Explain your answer.