1. Human and Social Biology Photosynthesis Created by :Reynaldo Thomas

2. Photosynthesis
This is the process by which plants make their own food.
The raw materials are water
from soil and carbon dioxide
obtained from the air.
The energy from sun light is
use to Split water molecules
into oxygen and hydrogen.
Sunlight also help to convert
Carbon dioxide and water to
glucose.

3. Stages of Photosynthesis
Light reaction stage
This occurs when the light energy from the sun is taken in by chlorophyll in
chloroplasts.
This energy splits the water
into hydrogen and oxygen.
The oxygen passes out of the
plant as a waste product to
the atmosphere.

4. Dark reaction
This is where the hydrogen combines with the carbon dioxide to produce the
sugar/glucose.

5. How plant leaves help photosynthesis
They are thin and flat which increase it surface area.
Leaf absorbed light energy.
Surfaces of the leaves
contain tiny pores called
stomata (sing,,,stoma)
Carbon dioxide diffuse
from the atmosphere
through the pores.

6. Oxygen produced will diffuse out.
Plants use some of the sugars they make for respiration.
Most sugars are converted
to starch.
Starch is stored in the leaves
stem and root.

7. Importance of Photosynthesis
It provides an energy source that can be used by other living organisms.
It maintain the correct balance of oxygen and carbon dioxide levels in the atmosphere.
To provide food for the growing human population.