Posts Tagged ‘photosynthesis’

Photosynthesis

Friday, February 18th, 2011

Jatropha hybdrid - leaf detail by tonrulkens on flickr

And here is the sing-along song for this topic.

For notes on the SL portion of the syllabus, here is a useful powerpoint.  Photosynthesis  This is the core material from our favourite teacher in Indonesia.  Once you have grasped the basics, move on to this HL stuff.

We’ll cover a lot of interesting ideas in this unit.  How are plants affected by light of different wavelengths?  What is the relationship between structure and function in chloroplasts? What is meant by limiting factors in determining photosynthetic rate?  How can we measure photosynthesis?  And, of course, we’ll delve into the biochemical pathways of the light dependent and light independent reactions.

Useful video for labs.

There are 3 online photosynthesis simulations that we will use.  This first one is nice and simple and should help get you started on your design lab.  This one is also easy to use.  This third one is more complicated, and you might want to come back to it as we go through the topic.

Creativity with carbon

Tuesday, November 16th, 2010

Imagine you are a carbon atom in a molecule of carbon dioxide in the air.  Close your eyes.  Really imagine yourself as that carbon atom.  Your task is to describe the journey you take from being part of carbon dioxide in the air, through the carbon cycle, until you return to the air again.  Here is my attempt at the beginnings of such a story to give you the idea.  You do not need to start in this way.  You decide.  Get creative!  Let your imagination work!

There I was, happily floating around in my usual gaseous form along with several of my brothers and sisters  (other carbon dioxide molecules), and my good friends nitrogen and oxygen.  We were having a great time bumping into one another, when I got dangerously close to a leaf.  Everyone had always told me to stay away from green plants, that I could get sucked into a stoma and never be seen again.  Before I realized what was happening, I was inside a chloroplast and going through a very fast reaction where I had to let go of my two oxygen atoms, and for a moment be entirely alone.  Before long, I found some other carbons and we joined together, 6 of us, 12 hydrogen friends and 6 oxygen buddies to form a glucose molecule….

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.

Life processes

Wednesday, October 20th, 2010

Photosynthesis by One-Speed Photography on flickr

The two most important processes for living organisms are RESPIRATION and PHOTOSYNTHESIS.  As we learn about these, you must keep in mind what each has to do with ENERGY

Look at this document.  It is a webquest that will guide you through the main points to remember about respiration and photosynthesis.  Thanks to Mr Goodman for putting it together for us 🙂

Respiration and Photosynthesis Web quest

Creativity with Carbon

Friday, February 19th, 2010

Imagine you are a carbon atom in a molecule of carbon dioxide in the air.  Close your eyes.  Really imagine yourself as that carbon atom.  Your task is to describe the journey you take from being part of carbon dioxide in the air, through the carbon cycle, until you return to the air again.  Here is my attempt at the beginnings of such a story to give you the idea.  You do not need to start in this way.  You decide.  Get creative!  Let your imagination work!

There I was, happily floating around in my usual gaseous form along with several of my brothers and sisters  (other carbon dioxide molecules), and my good friends nitrogen and oxygen.  We were having a great time bumping into one another, when I got dangerously close to a leaf.  Everyone had always told me to stay away from green plants, that I could get sucked into a stoma and never be seen again.  Before I realized what was happening, I was inside a chloroplast and going through a very fast reaction where I had to let go of my two oxygen atoms, and for a moment be entirely alone.  Before long, I found some other carbons and we joined together, 6 of us, 12 hydrogen friends and 6 oxygen buddies to form a glucose molecule….

Carbon cycle

Thursday, February 11th, 2010
Nature by jaxxon on flickr

Nature by jaxxon on flickr

We’re going to try and connect all that we have been learning – respiration, combustion, photosynthesis, food chains – into one big carbon cycle. This brainpop video will help get you started.  

This one on fossil fuels explains where oil, coal and gas come from, and leads into our next section on the importance of oil and how to separate it out by distillation.  This video explains how this works in an oil refinery. We’ll do a world energy audit and look at where the natural resources are and what the alternative energy sources might be.

Greenhouses and photosynthesis

Thursday, January 28th, 2010

Take a look at this sheet (thanks Mr Boulton).  Greenhouse Assessment Task

It gives some background info on how greenhouses work, and finishes with some questions about the links with photosynthesis and respiration.

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?