1. which is limiting at a particular time depends on the environment conditions:
-at night the light is the limiting factor
-in winter the temperature is the limiting factor
-if its warm enough and bright enough the amount of carbon dioxide is usually
limiting
An experiment can be done to work out the ideal conditions for photosynthesis in a particular plant
for example you can use a canadian ponweed
You would measure the amount of oxygen produced in a given time to show how fast photosynthesis is happening
Oxygen is produced during photosynthesis
Count the bubbles given off, or to be more accurate collect the oxygen in a gas syringe
There are three important graphs for rate of photosynthesis
1. Not enough light slows down the rate of photosynthesis
Light= energy needed for photosynthesis. As the light levels
raise the rate of photosynthesis increases but only to a certain point
Beyond that certain point the amount of light will not make a
difference because it would be the temperature or the CO2 levels which are the limiting factors
In a lab you can move a lamp closer to the plant to increase the rate of photosynthesis
If you plot the rate of photosynthesis against the ''distance from the beaker'' you would get a weird
shape graph. To get a a nice smooth curve you either need to measure the light intensity at the
beaker using a light meter or do some maths with the results
2.Too little carbon dioxide also slows down the rate of photosynthesis
CO2 is one of the raw materials for photosynthesis
CO2 will only increase the rate of photosynthesis to a certain point then it will not longer increase
photosynthesis
As long as the light and CO2 are available then the limiting factor for photosynthesis is temperature
There are different ways to control the amount of CO2
one is to dissolve different amounts of sodium hydrogencarbonate in the water, which gives off CO2