B4.1 Photosynthesis Flashcards
State the word equation for photosynthesis.
Carbon dioxide + water -> glucose + oxygen (light above the arrow)
State the balanced chemical symbol equation for photosynthesis.
6CO2 + 6H2O -> C6H12O6 + 6O2
Is photosynthesis an endo- or exothermic reaction?
Endothermic.
What energy transfer occurs in photosynthesis?
Light energy to chemical energy.
Where does photosynthesis occur in a plant or algal cell?
Chloroplasts.
What are chloroplasts filled with?
Chlorophyll.
What is the function of chlorophyll?
Captures light energy.
Name the three factors which affect the rate of photosynthesis.
Temperature, light intensity, carbon dioxide concentration
What is the inverse square law?
Light intensity is directly proportional to 1/distance^2
How does the inverse square law apply to photosynthesis?
The intensity of light is inversely proportional to the square of the distance from the light source.
What does the inverse square law mean in practice when considering how plants grow?
When the light is moved twice as far from the plant it will receive a quarter of the energy.
Why can’t a commercial grower of plants just increase all three limiting factors of PHS to maximum levels to obtain optimum growth?
Light, temperature and CO2 all cost money to supply – a balance between expenditure and income must be struck for a profit to be made.
Name three ways glucose produced in photosynthesis is used in plants.
Used for respiration, converted into insoluble starch for storage, used to produce fat or oil for storage, used to produce cellulose which strengthens the cell wall and/or used to produce amino acids for protein synthesis.
What else, other than glucose, do plants need to produce proteins?
Nitrate ions.
Where are mineral ions absorbed from and through which plant organ?
From the soil, through the roots.
