1. Chapter 2 : Lesson 1
Photosynthesis

2. PHOTOSYNTHESIS How Do Living Things Get Energy From the Sun?
Read pg. 45 and talk about Figure 1

3. The Sun as an Energy Source
Photosynthesis – the process by which a cell captures energy in sunlight and uses it to make food
The food is called glucose

4. The Sun as an Energy Source
Nearly all living things obtain energy either directly or indirectly from the energy of sunlight that is captured during photosynthesis

5. Producers and Consumers
Producers make their own food – also known as autotrophs
Consumers don’t make their own food – also known as heterotrophs
Many heterotrophs get food from eating other organisms

6. What Happens During Photosynthesis?
During photosynthesis, plants and some other organisms absorb energy from the sun and use the energy to convert carbon dioxide and water into sugars and oxygen

7. Takes place in two stages: 1. Plants capture sun’s energy
What Happens During Photosynthesis?
Takes place in two stages:
1. Plants capture sun’s energy
2. plants produce sugars
More detail about both stages on next slide…

8. What Happens During Photosynthesis?

9. Chlorophyll – the main pigment for photosynthesis
Stage 1: Capturing the Sun’s Energy
Chlorophyll – the main pigment for photosynthesis
1. Plants capture sun’s energy
2. plants produce sugars
More detail about both stages on next slide…

10. Chlorophyll – the main pigment for photosynthesis
Stage 1: Capturing the Sun’s Energy
Chlorophyll – the main pigment for photosynthesis
1. Chlorophyll captures energy from sunlight
a. Happens mostly in leaves

11. b. Water in the chloroplasts is split into hydrogen and oxygen.
Stage 1: Capturing the Sun’s Energy
b. Water in the chloroplasts is split into hydrogen and oxygen.
c. Oxygen is given off as a waste product
d. The hydrogen is used in stage 2

12. Stage 1:
First Stage of Photosynthesis
The first stage of photosynthesis powers the “energy engine” of the living world.

13. Stage 1:
Virtual Lab???

14. Stage 1: Plants capture sun’s energy Stage 2: plants produce sugars
Remember…2 stages of photosynthesis
Stage 1: Plants capture sun’s energy
Stage 2: plants produce sugars

15. Photosynthesis
What is the process of photosynthesis?

16. Photosynthesis
What is the process of photosynthesis?
Light energy is changed to cell energy
Sugars are produced

17. Cells produce sugars in stage 2 The sugar is glucose – C6H12O6
Stage 2: Using Energy to Make Food
Cells produce sugars in stage 2
The sugar is glucose – C6H12O6
Water and carbon dioxide combine chemically to form sugars – oxygen is released

18. Producing Food
The second stage of photosynthesis makes food for a plant. How can the information for Stage 1 and Stage 2 be completed?

19. Producing Food
The second stage of photosynthesis makes food for a plant. How can the information for Stage 1 and Stage 2 be completed?
chlorophyll
sunlight
energy
Carbon dioxide
sugars

20. The Photosynthesis Equation
Light Energy L
6O2
Light Energy
Light
Raw materials - materials needed for the chemical reaction to occur – (the molecules on left side of equation) – light energy is not a raw material, but written on the left to show it’s used in the reaction
6 molecules of carbon dioxide and 6 molecules of water

21. The Photosynthesis Equation
Light Energy
Light Energy
6O2 L
Light
Products – compounds that were chemically combined after the reaction – (the molecules on right side of equation)
1 molecule of glucose and 6 molecules of oxygen

22. Circle two products of photosynthesis? Glucose c. Carbon dioxide
Assess Your Understanding
Circle two products of photosynthesis?
Glucose c. Carbon dioxide
Oxygen d. Chlorophyll

23. 2a. Circle two products of photosynthesis? Glucose c. Carbon dioxide
Assess Your Understanding
2a. Circle two products of photosynthesis?
Glucose c. Carbon dioxide
Oxygen d. Chlorophyll

24. Assess Your Understanding
2b. Refer to figure 3 on pg Where does the hydrogen that is used in Stage 2 of photosynthesis come from?

25. Assess Your Understanding
2b. Refer to figure 3 on pg Where does the hydrogen that is used in Stage 2 of photosynthesis come from?
Hydrogen comes from water that is split apart in Stage 1.

26. Assess Your Understanding
c. Would you expect a plant to produce more oxygen on a sunny day or a cloudy day? Explain.
vs.

27. Assess Your Understanding
c. Would you expect a plant to produce more oxygen on a sunny day or a cloudy day? Explain.
vs.
On a sunny day; more sunlight would be available for photosynthesis

28. I get it! Now I know that during photosynthesis…
Assess Your Understanding
I get it! Now I know that during photosynthesis…

29. I get it! Now I know that during photosynthesis…
Assess Your Understanding
I get it! Now I know that during photosynthesis…
Plants absorb energy from the sun and produce sugar (food) and oxygen.

30. What are the two raw materials of photosynthesis?
One more to check
What are the two raw materials of photosynthesis?
Glucose c. Carbon dioxide
Water d. Oxygen

31. What are the two raw materials of photosynthesis?
One more to check
What are the two raw materials of photosynthesis?
Glucose c. Carbon dioxide
Water d. Oxygen