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Task 1 :A/S GROUP 2007-2008, Read the section on microscopy. All of you should aim to post me a least one comment before next lesson! In your comments answer the two following questions:

1. Explain why a scanning electron microscope produces more detailed images of cells than a light microscope.
2. Give two disadvantages of using a transmission electron microscope.
   

For a comprehensive revision list check out the AQA Biology B specification

MODULE 1 CORE PRINCIPLES
Please check out and make revision notes from the following webpages.
Carbohydrates
Proteins
Lipids
Enzymes
Eukaryotic Cells Structure
Prokaryotic Cell Structure
Comparing the two
Test on Cells
Transport
Diffusion, Osmosis, Active Transport
Microscopy



Task 2 : Post me a comment, answering the next section of questions:

1. How does the structure of glycogen differ from starch and cellulose [3]
2. Give two ways in which starch is an ideal sorage compound in plants. [2]
3. How could you test some onion cells to see if they contained starch? [2]
4. How are cellulose molecules arranged in cell walls of plants? [3]
   

Task 3: Answer these questions on Enzymes.

1. What is meant by the 'specficity of enzymes'? [1]
2. How does the lock and key hypothesis account for the specificity of enzymes? [3]
3. How does the induced fit hypothesis differ from the lock and key hypothesis? [2]
4. Explain the effect of increasing the temperature above the optimum on enzyme activity [4]
5. Explain how enzymes are able to catalyse biological reactions. [2]
6. Describe how a non-competitive inhibitor prevents enzyme activity. [3]