3.8+Photosynthesis

3 Chemistry of Life - 3.1 Chemical elements and water - 3.2 Carbohydrates, proteins and lipids - 3.3 DNA structure - 3.4 DNA replication - 3.5 Transcription and translation - 3.6 Enzymes - 3.7 Cell respiration - 3.8 Photosynthesis - Biochemistry Labs - DNA Labs

3.8 Photosynthesis
This sub-topic is a good introduction to the more detailed understanding required by 8.2/C4 Photosynthesis.


 * Assessment statements** (IBO notes added to some points to clearly indicate what needs to be understood and what does not)
 * 3.8.1 || State that photosynthesis involves the conversion of light energy into chemical energy. ||
 * 3.8.2 || State that light from the Sun is composed of a range of wavelengths (colours). Reference to actual wavelengths or frequencies is not expected. ||
 * 3.8.3 || State that chlorophyll is the main photosynthetic pigment. ||
 * 3.8.4 || Outline the differences in absorption of red, blue and green light by chlorophyll. Pigments absorb certain colours of light, the remaining colours of light are reflected. ||
 * 3.8.5 || State that light energy is used to produce ATP, and to split water molecules (photolysis) to form oxygen and hydrogen. ||
 * 3.8.6 || State that ATP and hydrogen (derived from the photolysis of water) are used to fix carbon dioxide to make organic molecules. ||
 * 3.8.7 || Explain that the rate of photosynthesis can be measured directly by the production of oxygen or the uptake of carbon dioxide, or indirectly by an increase in biomass. ||
 * 3.8.8 || Outline the effects of temperature, light intensity and carbon dioxide concentration on the rate of photosynthesis. The shape of the graphs is required. The concept of limiting factors is not expected. ||

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="23823666"


 * Presentations and tutorials **

Biostuff has a basic [|introduction to photosynthesis] for SL students covering the assessment statements

Pictures can sum up simply a thousand words. This is a good example which can help to visualise the light-dependent and independent reactions in the metabolic pathway of photosynthesis //Edited from original source: //

The khan academy video on photosynthesis gives a good overview and goes into more detail, some not necessary for SL students, be aware of your assessment statements media type="custom" key="23823670"

Steven Taylor ( [|i-Biology] ) has a great presentation to view and take notes from before starting your notebook media type="custom" key="23823672"

Use [|click4biology] to review and complete your notes


 * Suggested Activities**

Starters: what can you remember about photosynthesis from previous studies? Write down as much as you can on the board.

Learning through labs
 * Separate the different photosynthetic pigments and calculate their Rf values - see biochemistry labs. You can also use a spectrophotometer to see the action spectrum of the photosynthetic pigments you extracted.
 * You need to understand how to measure photosynthesis and how temperature, light intensity and carbon dioxide concentration affect it. Under biochemistry labs look at the simulations and try out [|The Floating Leaf Disk Assay for Investigating Photosynthesis] before moving on to designing your own lab

Notes: work on your notes either by yourself or in small groups. Take advantage of the mini-tutorials sessions when needed.

Extension: after finishing your notes, review your practical work. Design a carry out a lab investigating photosynthesis. Look at an aspect of photosynthesis that interests you. Remember to frame your research question properly and source relevant background information. Check your design with your teacher before moving on and collecting data.


 * Useful Links **

This rap is for fun, but also has some good details about photosynthesis. Enjoy. media type="custom" key="25667814"