6.2 Photosynthesis

Photosynthesis

Core

Define Photosynthesis

State the word equation for the production of 

simple sugars and oxygen

Describe the intake of carbon dioxide and water 

by plants

Explain that chlorophyll traps light energy 

and converts it into chemical energy for the 

formation of carbohydrates and their subsequent 

storage

Extended

State the balanced equation for 

photosynthesis in symbols

Investigate and state the effect of varying 

light intensity, carbon dioxide concentration 

and temperature on the rate of photosynthesis 

(e.g. in submerged aquatic plants)

Define the term limiting factor as something 

present in the environment in such short 

supply that it restricts life processes

Explain the concept of limiting factors in 

photosynthesis

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Photosynthesis is the process by which plants produce Carbohydrates from raw materials by trapping light.

Word Equation for simple sugars and oxygen

Carbon Dioxide + Water --------> Glucose + Oxygen

Water is taken from soil by root hair cells, this water travels up the xylem tubing since there is a lower pressure at the top (transpiration causing water on leaves of plant to evaporate meaning there is a lower pressure up, constantly) Carbon Dioxide is taken into the plant by process of diffusion whilst Stomata on the plant leaves are open, the C02 diffuses into the plant leaves and spreads around.

Varying light intensity on a plant may adversely damage it. If an plant only receives a very low level of light, it will not photosynthesize as much as a plant in normal light and this is because there is less light being converted into chemical energy for the plant to actually undergo the process of photosynthesis. Low levels of C02 would also adversely affect the plant as it would be missing one half of the requirements for photosynthesis. Although too much of these two substances would not harm the plant, at a certain point the rate of photosynthesis neither speeds up or decreases. Low temperature means chemical reactions can not take place as fast as normal and so the rate of photosynthesis is decreased, once again though a certain point is reached as temperature increases and the rate of photosynthesis will no longer increase.

A limiting factor is a factor of the environment which has a certain impact on the rate of photosynthesis of a plant. For example C02 and Temperature can be limiting factors if they are low (temp) or sparsely found (levels of C02)