The Rate of Photosynthesis. Flashcards
What is the rate of photosynthesis affected by?
Intensity of light.
Volume of CO2.
Temperature .
When a plant is short of something then it becomes what?
Limiting factor in photosynthesis.
The limiting factor depends on what?
The conditions.
What does the limiting factor do?
Stops photosynthesis from happening any faster.
Which factor is limiting at a particular time depends on what?
The environmental conditions.
At night what is the limiting factor?
Light.
In winter what is the limiting factor?
Temperature.
If its warm enough and bright enough, what is the limiting factor?
The amount of CO2.
You can do experiments to work out the…
Ideal conditions for photosynthesis in a particular plant.
What is the easiest type of plant to use?
Water plant.
Canadian pondweed.
How is Canadian pondweed easy to use?
Easily measure the amount of oxygen produced in a given time to show how fast photosynthesis is happening.
What is made during photosynthesis?
Oxygen.
How can you measure the amount of oxygen produced?
Count bubbles given off.
Collect the oxygen in a gas syringe - accurate.
How many important graphs are there for rate of photosynthesis?
3.
Not enough light slows down what?
Rate of photosynthesis.
Light provides what?
Energy needed for photosynthesis.
If the light level is raised then what happens?
Rate of photosynthesis increases steadily.
Only to a certain point.
Beyond a certain point why wont the light level make a difference?
It will either be temperature or CO2 which is the limiting factor.
If you plot the rate of photosynthesis against ‘the distance of lamp from the beaker’ what do you get?
Weird-shape graph.
To get a correct graph what do you need to measure?
Light intensity at the beaker using light meter.
Too little carbon dioxide slows down what?
Rate of photosynthesis.
The amount of CO2 only increases the rate of photosynthesis until…
A certain point.
When the graph flattens it shows that Co2?
Not the limiting factor anymore.
Name a way to control the amount of CO2?
Dissolve different amounts of sodium hydrogen-carbonate in the water, which gives of CO2.
The temperature has to be…
Just right.
If the temperature is the limiting factor its v=because…
Its too low.
Enzymes needed for photosynthesis work…
Slowly at low temperatures.
What happens if the plant gets too hot?
Enzymes needed for photosynthesis will be damaged.
What temp do the enzymes become damaged?
About 45 degrees.
What is the best way to control the temp?
Put flask in a water bath.
