B4 Flashcards
What is photosynthesis?
An endothermic reaction (requires input energy) in which energy is transferred from the environment to the chloroplasts by light
State the word equation for photosynthesis
……………………………………..Light
Carbon dioxide + Water ——–> Glucose+Oxygen
Chlorophyll
What is the symbol equation for photosynthesis?
6CO2 + 6H2O —————–> C6H12O6 + 6O2
What is the effects of temperature on photosynthesis?
- At low temperatures, the rate of photosynthesis is limited by the number of collisions between enzymes and substrate
- As temperature increases the number of collisions increases, therefore the rate of photosynthesis increases
What is the effects of light intensity on photosynthesis?
The rate of photosynthesis is directly proportional to light intensity and inversely proportional to the distance from a light source
What can be described because of the inverse square law?
The intensity of light at different distances from a light source
What is the effects of carbon dioxide concentration on photosynthesis?
If the concentration of carbon dioxide is increased, the rate of photosynthesis will therefore increase.
What is the effects of the amount of chlorophyll concentration on photosynthesis?
- The amount of chlorophyll also affects the rate of photosynthesis: plants in lighting conditions unfavourable for photosynthesis synthesise more chlorophyll, to absorb the light required.
- The effects of some plant diseases affect the amount of chlorophyll, and therefore the ability of a plant to photosynthesise.
What are the limiting factors in photosynthesis (stops making photosynthesis happen any faster) ?
Intensity of light, CO2 concentration and temperature
Note:
AQA says that students should be able to:
- Measure and calculate rates of photosynthesis
- Extract and interpret graphs of photosynthesis rate involving one limiting factor
- Plot and draw appropriate graphs selecting appropriate scale for axes
- Translate information between graphical and numeric form
(Check goodnotes Biology B8 Folder which has the rate of photosynthesis with explanations)
Note:
AQA says that students should be able to explain graphs of photosynthesis rate involving two or three factors and decide which is the limiting factor
Why are limiting factors important in the economics of farmers?
As they need to enhance the conditions in greenhouses to gain the maximum rate of photosynthesis while still maintaining profit
What do farmers do to enhance the conditions in greenhouses?
- Plants in greenhouses are often sprayed with water to keep the humidity high
- Growers must find a balance as high humidity will promote the growth of pathogenic fungi
- Irrigation systems are also used outdoors
- Ventilation is also used
Practical 5
AAA
What is the glucose produced in photosynthesis used for?
- 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
- Used to produce amino acids for protein synthesis