Posts Tagged ‘limiting factors’

More photosynthesis and respiration …

Friday, November 5th, 2010

Photosynthesis on the act by andredoreto on flickr

Welcome back after a well-deserved break.  Now to pick up where we left off …

We will be doing an online photosynthesis simulation using explorelearning.  You will need to log in with username and password.  These are the same as for brainpop.  Click on launch gizmo on the photosynthesis lab.  You can then experiment by changing several factors and seeing how it affects the rate.  Here are some questions to answer:

  • What effect does changing temperature have on the rate of photosynthesis?
  • What effect does changing light intensity have on the rate of photosynthesis?
  • What effect does changing carbon dioxide concentration have on the rate of photosynthesis?
  • What effect does changing the colour of light (wavelength) have on the rate of photosynthesis?

For each of these, can you sketch the shape of the graph.  Don’t forget to label the axes.

We will be discussing the concept of limiting factors.  We will use the data in this excel document for this. Limiting factors data

You can check out this post by Mr Duckworth for some extra help as well.

Limiting factors in photosynthesis

Wednesday, January 27th, 2010
photosynthesis in action by Sam Judson on flickr

photosynthesis in action by Sam Judson on flickr

Let’s suppose I want to redecorate my bedroom.  I need money to buy the materials, I need to know how to decorate, and I need the time to be able to do it.  Imagine that I am a good decorator, with a free weekend coming up, but I have no money to buy what I need.  The materials are the limiting factor in this instance.  The lack of paints, brushes, wallpaper, etc is what is stopping the process of redecoration.  Similarly, if I had money and knowledge, but was busy for the next month, then time would be the limiting factor.

Limiting factors apply to photosynthesis too.  We’ll discuss the factors that control how fast or how slowly photosynthesis proceeds, and analyse some graphs to help us understand this concept.

Is the main limiting factor for photosynthesis different in different parts of the world?  Or for different species of plants?  What do you think?