· During day time the stomata remain open. Through the stomata the leaves get air containing carbon-dioxide from the atmosphere.
· Water, mixed with minerals reaches the leaves from the soil through the different parts i.e. roots, stem, branches and twigs.
· Leaf cells have green pigment called chlorophyll.
· The sunlight reaches the leaves through their skin and is absorbed by the chlorophyll.
· Using the energy of sunlight absorbed by the chlorophyll leaves change water and carbon dioxide into sugar (glucose i.e. carbohydrates) and oxygen is given out.
· Some of the sugar is used by the plant as food to grow. Some of the sugar is changed into starch.
· The rest of the sugar and the starch are stored in different parts of the plant.
The process of photosynthesis may be represented as-
FACTORS AFFECTING PHOTOSYNTHESIS
For a constant rate of photosynthesis, various factors are needed at an optimum level. Here are some of the factors affecting photosynthesis.
- Light Intensity: An increased light intensity leads to a high rate of photosynthesis
and a low light intensity would mean low rate of photosynthesis
- Concentration of CO2: Higher carbon dioxide concentration increases the rate of photosynthesis.
- Temperature: An efficient photosynthesis requires an optimum temperature range between 25 to 35oC.
- Water: Lack of water leads to a problem for carbon dioxide intake. If water is scarce, the leaves refuse to open their stomata to keep water they have stored inside.
- Polluted Atmosphere: The pollutants and gases (impure carbon) settle on
leaves and block the stomata, making it difficult to take in carbon dioxide. A
polluted atmosphere can lead to a 15 percent decrease in the rate of