B8 photosynthesis Flashcards
Is photosynthesis endo or exothermic and why
It’s endothermic as it requires input energy from environment
Photosynthesis equation word and symbol
Carbon dioxide + water
-light- glucose + oxygen
CO2 + H2O -light- C6H12O6 + O2
What is done with the glucose produced by photosynthesis
Some used immediately by the cells of the plant for respiration but most converted to starch to store
Leaf adaptations for photosynthesis
- Large SA to absorb light
- Contain chlorophyll to absorb light
- Xylem supply’s water to leaf through veins
- Veins remove products via phloem
- Air spaces to allow CO2 to get into cells and O2 to leave
- Guard cells to open and close stomata to regulate gas exchange and water loss
Effect of light intensity on rate of photosynthesis
As light intensity increases rate of photosynthesis increases but plateaus after optimum level reached
Effect of temperature on rate of photosynthesis
Increasing or decreasing from optimum temperature results in lower rates of photosynthesis
Effects of carbon dioxide concentration on rate of photosynthesis
As carbon dioxide concentration increases rate of photosynthesis increases but plateaus after optimum levels are reached
Examples of where glucose is used in a plant
- Produce amino acids
- Produce cellulose
- Respiration
- Produce fat or oil for storage
What’s the yield of a plant
The amount of crop grown
3 examples of where yield can be optimised
Glass houses, polytunnels, hydroponic growing
How to investigate the effects of light intensity on rate of photosynthesis using aquatic organisms such as pondweed
1.
What is hypothesis
Changing the light intensity will affect rates of photosynthesis
Conclusion from practical investigating light intensity to rate of photosynthesis
As light intensity increases rate of photosynthesis increases up to the point where another factor may be limiting
What is it called when something increases the other decreases
Inverse relationship - but the relationship between light intensity and rate of photosynthesis follows the inverse square law
Equation for light intensity
Light intensity = 1/distance squared
