4.4.1.2 rate of photosynthesis (HT) Flashcards
Explain the shape of the graph at point A.
The rate of photosynthesis is increasing as temperature increases.
Becauses enzymes and substrates have more kinetic energy.
So there are more successful collisions.
Explain the shape of the line at point B on the graph:
Photosynthesis is happening at its optimum rate.
Becauses enzymes and substrates have maximum kinetic energy.
So there are maximum possible successful collisions.
DESCRIBE the graph below:
As temperature increases, rate of photosynthesis increases.
A maximum rate is reached.
Then the rate ogf photosynthesis decreases rapidly past the optimum temperature and stops at 45°C
Remember: you must include numbers from axis if they are given!!
Identify the limiting factor/s at point B
Explain how you know.
CO2 conc/Temperature/Chlorophyll/Water
Because when light intensity increases past this point rate of photosynthesis does not - so must be one of the other factors.
Identify the limiting factor at point A.
Explain how you know.
CO2 concentration.
because as CO2 concentration increases so does the rate of photosynthesis
What is the symbol for nitrates?
NO3-
DESCRIBE the graph below…
As light intensity is increases rate of photosynthesis increases.
Eventually, the rate of photosynthesis remains constant.
Remember: if numbers are on the axis’ you mst include them in your description!!
Identify the limiting factor at point A.
Explain how you know.
Amount of light
because as light intensity increases so does the rate of photosynthesis
Identify the limiting factor/s at point B.
Explain how you know.
Light Intensity/Temperature/Chlorophyll/Water
Because when CO2 concentration increases past this point rate of photosynthesis does not - so must be one of the other factors.
Explain the shape of the graph at point C.
The rate of photosnthesis is decreasing rapidy past the optimum temperature.
Because enzymes are denaturing.
Change to shape of active site.
Fewer successful collisions.
DESCRIBE the graph below:
As CO2 concentration is increases rate of photosynthesis increases.
Eventually, the rate of photosynthesis remains constant.
Remember: if numbers are on the axis’ you mst include them in your description!!
As you move a plant away from a lamp, the light intensity reaching the plant decreases. We say that distance and light intensity are i__________ p_____________.
inversely proportional
How can we calculate the light intensity coming from a lamp that is reaching a plant?
The Inverse Square Law
Light intensity = 1 ÷ Distance of plant from lamp²
How do farmers optimise conditions for photosynthesis?
The grow crops in a greenhouse.
How do greenhouses optimise photosynthesis?
- Artificial lighting allows photosynthesis to occur at night.
- Shades - can be shut if it gets too warm.
- Propane burner - releases CO2
- Maintain optimum temp for photosnyhtesis.
- Glass allows light to reach crops.
- Fertilisers can be used to supply minerals e.g. magnesium
