1. Photosynthesis: Life from Light and Air
Unit 4 – Lesson 2

2. Plants are Energy Producers
Plants are able to make both FOOD & ENERGY
In this lesson, we will discuss HOW this happens.

3. How do Plants Make Energy & Food?
Plants need water and carbon dioxide
water is taken in by the roots
carbon dioxide is taken in by the leaves
CO2
H2O

4. How do Plants Make Energy & Food?
Plants need the energy from the sun
Once the plant has CO2 and H2O, it uses sunlight to convert the materials into sugar (food).
sun
sugars

5. Chloroplasts Leaf Leaf Cells Chloroplast Chloroplasts Contain
Chlorophyll

6. How do Plants Make Energy & Food?
Types of sugars made in plants:
glucose, sucrose, cellulose, starch, & more
The plants need to make these sugars for their own nutrition…but other animals benefit from the plants sugars too!

7. How do Plants Make Energy & Food?
The sugar made is stored in the plant.
The O2 waste product gets used for respiration or is released into atmosphere. O2

8. The Complete Equation  + CO2 H2O C6H12O6 O2 light energy
Carbon Dioxide
Water
Glucose
Oxygen

9. Leaf Structure

10. Function of Leaf Structures
Waxy Cuticle
waxy coating reduces water loss
Epidermis
skin protecting leaf tissues

11. Function of Leaf Structures
Stomata – small openings in the epidermis of the leaf. Lets materials in and out.
CO2
H2O O2
The stomata opens and closes because of guard cells surrounding it.

12. Stomates & Guard Cells
sun
Transpiration!

13. Function of Leaf Structure
Inside the leaf are two layers of cells, the spongy layer and the palisade layer.
Materials, like sugar, get stored in the spongy layer.
Most of the food is made in the palisade layer.

14. How do Plants Make Energy & Food?
What does the plant do once it has sugar?
Breaks it down for ENERGY
We call this Cellular Respiration
takes in the sugar molecule it makes and uses oxygen to make energy
This happens in the MITOCHONDRIA
ATP is the energy used in ALL LIFE
sugars O2
CO2
H2O
carbon dioxide
CO2
ATP
sugars
C6H12O6
oxygen O2
water
H2O + + +

15. Photosynthesis vs. Respiration
Energy
Starting Products
End Products
Where
Photosynthesis
Respiration
Water and
Carbon Dioxide
Glucose and
Oxygen
Cells with
Chlorophyll
Stored from the SUN
Released in form of ATP
Glucose and
Oxygen
Water and
Carbon Dioxide
Cells with
Mitochondria
YouTube / Video Link

16. Energy Cycle ATP Photosynthesis Cellular Respiration sun CO2 O2 H2O
plants
H2O
CO2
glucose sugars O2
animals, plants
Cellular Respiration
ATP

17. The Poetic Perspective
All of the solid material of every plant was built out of thin air
All of the solid material of every animal was built from plant material
sun
air
Then all the cats, dogs, mice, people & elephants… are really strands of air woven together by sunlight!