Photosynthesis

What is needed for photosynthesis to occur?

1. Carbon dioxide

• Comes from air.
• Enters the leaf through stomata.

2. Water

• Comes from the soil.
• Enters through the roots.

3. Sunlight

• Absorbed by leaves (chlorophyll within chloroplasts).
• Provides the energy needed for photosynthesis to occur.

4. Chlorophyll

• Green pigment within chloroplasts in the leaves.
• Absorbs light energy.

What are the products of photosynthesis?

5. Glucose

• Type of sugar used by plant for energy.
• Excess glucose is stored in the form of starch.

6. Oxygen

• By-product of photosynthesis.
• Used in plant respiration.
• Excess is released through stomata.

Process of Photosynthesis

1. Plants absorb carbon dioxide (CO₂) from the air through tiny pores in their leaves known as stomata.
2. Water is taken up through the roots from the soil.
3. Sunlight provides the energy needed for photosynthesis. It is captured by the green pigment chlorophyll within chloroplasts in the leaves.
4. This process converts water and carbon dioxide into glucose and oxygen. The oxygen is then released back into the air through the stomata.

Photosynthesis Equation

This illustrates that carbon dioxide and water, using light energy, are transformed into glucose and oxygen.

Importance of Photosynthesis

1. It generates oxygen, essential for respiration in most living organisms.
2. It provides the primary source of nutrition for plants, and indirectly for animals.
3. By reducing atmospheric CO2 levels, it lessens the impact of global warming.

Factors Affecting Photosynthesis

• Light: The intensity and duration of light exposure affect the rate of photosynthesis.
• Carbon Dioxide: The amount of available CO₂ controls the rate of photosynthesis.