8.2+Photosynthesis

8. Cell Respiration and Photosynthesis AHL - 8.1 Respiration - 8.2 Photosynthesis

8.2 Photosynthesis
Core (3.8) photosynthesis is a good introduction to the more detailed understanding required by this sub-topic. N.B. This sub-topic directly corresponds to option C4.


 * Assessment statements** (IBO notes added to some points to clearly indicate what needs to be understood and what does not)
 * //8.2.1// || //Draw and label a diagram showing the structure of a chloroplast as seen in electron micrographs.// ||
 * //8.2.2// || //State that photosynthesis consists of light-dependent and light-independent reactions. These should not be called “light” and “dark” reactions.// ||
 * //8.2.3// || //Explain the light-dependent reactions. Include the photoactivation of photosystem II, photolysis of water, electron transport, cyclic and non-cyclic photophosphorylation, photoactivation of photosystem I, and reduction of NADP+.// ||
 * //8.2.4// || //Explain photophosphorylation in terms of chemiosmosis.// ||
 * //8.2.5// || //Explain the light-independent reactions. Include the roles of ribulose bisphosphate (RuBP) carboxylase, reduction of glycerate 3-phosphate (GP) to triose phosphate (TP), NADPH + H+, ATP, regeneration of RuBP, and subsequent synthesis of more complex carbohydrates.// ||
 * //8.2.6// || //Explain the relationship between the structure of the chloroplast and its function. Limit this to the large surface area of thylakoids for light absorption, the small space inside thylakoids for accumulation of protons, and the fluid stroma for the enzymes of the Calvin cycle.// ||
 * //8.2.7// || //Explain the relationship between the action spectrum and the absorption spectrum of photosynthetic pigments in green plants. A separate spectrum for each pigment (chlorophyll a, chlorophyll b, and so on) is not required.// ||
 * //8.2.8// || //Explain the concept of limiting factors in photosynthesis, with reference to light intensity, temperature and concentration of carbon dioxide.// ||

Use chromatography to separate the photosynthetic pigments. Describe and explain the absorption of the different pigments. Now suggest what the relationship is between the absorption of the different pigments and the action spectrum of photosynthesis.
 * Starter**

Adapted from csuchico.edu

This activity can be done as class or group discussions. The result of the discussion can be used in for class notes against the assessment statement 8.2.7.

N.B. Although assessment statement 8.2.7 details "//A separate spectrum for each pigment (chlorophyll a, chlorophyll b, and so on) is not required//" the inclusion of the the different pigments allows students to development a better understanding.

Log in to the [|DCS Bridge] to obtain your workbooks and supporting resources
 * Workbooks and Worksheets **

An alternative set of notes from [|i-Biology] can be found here media type="custom" key="23823640"

Steven Taylor ([|i-Biology]) has a great presentation to view and take notes from before starting your notebook media type="custom" key="23823642"
 * Presentations and tutorials **

A great lecture and notes from the University of Illinois on photosynthesis

This tutorial is good for understanding the [|chloroplast]. It address photosynthesis in detail taking the chloroplast as the focal point.

Harvesting light from Sumanas Inc. is a nice tutorial which starts from the perspective of the leaf then zooms into the sub-cellular components and their roles.

The [|biostuff tutorial] on photosynthesis is a good IB centric information from which to start your notes.

Mr T Brown has a great animation to help in visualising the [|light reactions] in photosynthesis

Smith College has a good animation that can be used to help understand the light independent reactions

These great John Kyrk animations show the detail of photosynthesis. It's broken down into [|light dependent] and [|light independent] reactions.

[|Wiley tutorials on photosynthesis] are broken apart into stages and are presented in an accesible way.

Text based tutorial and notes from [|National Louis University]

This [|animation from St. Olaf College] shows an animation of the light dependent reactions and is a useful way to visualise learning gleaned from elsewhere.

This summary from [|Hartnell College] gives a good visual overview, great for understanding the concepts, but you need more depth and breath to meet your assessment statements.

Great Visualisation of Photosynthesis from NDVirtualCell Photosystem II Light reactions media type="custom" key="24479748"

Here's the Khan academy tutorials on photosynthesis broken down into: Light dependent reactions part 1 media type="custom" key="23823646" Photosynthesis: Light Reactions and Photophosphorylation media type="custom" key="23823648" Photosynthesis: Calvin Cycle media type="custom" key="23823650"

Use [|click4biology] to review and complete your notes


 * Approach **

__Teach and Test__

Your assessment statements for this topic are:
 * || Assessment statement || Detail ||
 * 8.2.1 || Draw and label a diagram showing the structure of a chloroplast as seen in electron micrographs. ||  ||
 * 8.2.2 || State that photosynthesis consists of light-dependent and light-independent reactions. || These should not be called “light” and “dark” reactions. ||
 * 8.2.3 || Explain the light-dependent reactions. || Include the photoactivation of photosystem II, photolysis of water, electron transport, cyclic and non-cyclic photophosphorylation, photoactivation of photosystem I, and reduction of NADP+. ||
 * 8.2.4 || Explain photophosphorylation in terms of chemiosmosis. ||  ||
 * 8.2.5 || Explain the light-independent reactions. || Include the roles of ribulose bisphosphate (RuBP) carboxylase, reduction of glycerate 3-phosphate (GP) to triose phosphate (TP), NADPH + H+, ATP, regeneration of RuBP, and subsequent synthesis of more complex carbohydrates. ||
 * 8.2.6 || Explain the relationship between the structure of the chloroplast and its function. || Limit this to the large surface area of thylakoids for light absorption, the small space inside thylakoids for accumulation of protons, and the fluid stroma for the enzymes of the Calvin cycle. ||
 * 8.2.7 || Explain the relationship between the action spectrum and the absorption spectrum of photosynthetic pigments in green plants. || A separate spectrum for each pigment (chlorophyll a, chlorophyll b, and so on) is not required. ||
 * 8.2.8 || Explain the concept of limiting factors in photosynthesis, with reference to light intensity, temperature and concentration of carbon dioxide. ||  ||

The class will divide into two groups, Biochemists and Generalists. Both groups will need to spit themselves into working groups containing 3-4 students. Ideally there will be an equal number of Biochemist and Generalist working groups.

The Biochemists will teaching 8.2.2 - 8.2.5, the Generalists will be teaching the remainder, i.e. 8.2.1, 8.2.6 - 8.2.8.

The aim of both groups is similar:
 * 1) Understand your assigned learning statements.
 * 2) Produce resources (laptops not allowed) to teach the other group.
 * 3) Produce a short test and mark scheme (maximum 15 marks) to test the success of your teaching and their learning.

The sequence of activities for each group is:
 * 1) Learn your assessment statements, remember to take notes or make diagrams (~20 mins)
 * 2) Produce a short test based on the assessment statements (~10 mins)
 * 3) Decide upon a teaching strategy and teaching resources (~20 mins)
 * 4) Take turns to teach other, Biochemists teach Generalists and vice-versa (~10 mins)
 * 5) Now sit the test the other group gave you (~10 mins)
 * 6) Take turns to mark your assessment and get feedback by discussing the mark scheme with your teacher group (~10 mins)

Summary questions
 * Summary and review**

__Review of the light dependent and independent reactions__ - this exercise is a useful way to both test your understanding and produce quality revision notes. Follow your teacher's guidance for how to complete it. media type="custom" key="23823636"