1. PHOTOSYNTHESIS

2. INTRODUCTION
All cells need energy. All cells get their energy in the form of chemical energy.
Chemical energy is the energy stored in the bonds between atoms of every molecule.

3. INTRODUCTION
Cells must be able to release energy stored in the bonds of their food molecules.
The molecule used by most organisms as an energy source is glucose.

4. INTRODUCTION
Plants make their own glucose, while animals must consume food in order to obtain glucose.

5. PHOTOSYNTHESIS
The source of energy for most organisms ultimately comes from the sun.
During the process of photosynthesis, plants change the light energy from the sun to the chemical energy (energy they can use) stored in the bonds of glucose molecules.

6. LOCATION
Photosynthesis takes place in plant cells that contain chloroplasts, i.e. leaves.
Chloroplasts contain chlorophyll, a light-absorbing pigment, that traps the energy in sunlight.

7. A CHEMICAL CHANGE Reactants Carbon dioxide (CO2) from the air
Water (H2O) from the soil

8. A CHEMICAL CHANGE Chemical Reaction
The energy trapped by the chlorophyll (sunlight) causes the atoms in carbon dioxide and the water to recombine and become new substances.

9. A CHEMICAL CHANGE Products
Glucose (sugar) – plants keeps for its energy needs
Oxygen (O2) – released in to the air

10. A CHEMICAL CHANGE Water + Carbon dioxide + Light energy
Glucose Oxygen

11. PHOTOSYNTHESIS GLUCOSE CHLOROPLAST OXYGEN WATER CARBON DIOXIDE
LIGHT ENERGY
OXYGEN
WATER

12. What type of cell performs photosynthesis?
Plant cell
Animal cell
Both plant and animal cells 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

13. Why does a plant cell perform photosynthesis?
To make water
To make carbon dioxide
To make food (glucose) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

14. What part of the plant cell does photosynthesis occur in?
Nucleus
Chloroplasts
Mitochondria 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

15. What does a plant cell need for photosynthesis?
Glucose, oxygen and sunlight
Carbon dioxide, water and sunlight
Oxygen, water and sunlight 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

16. What is produced during photosynthesis?
Glucose and oxygen
Carbon dioxide and water
Glucose and water 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30