Tutorial 6

1. Define:

• Aerobes• Obligate aerobes• Anaerobes• Obligate anaerobes• Microaerophiles• Capnophiles• Facultative anaerobes• Aerotolerant anaerobes2. Why do halophiles require sodium?3. What are the functions of compounds containing

a. Nitrogen in media?b. Phosphorus? c. Sulfur?

4. What are the energy sources for chemolithoautotrophs? 5. What is peptone? Is it chemically defined or undefined?6. What is an isolated colony and how can we obtain it?7. Explain the use of Sodium azide and its role in reducing the media.8. What difference does it make between storing bacteria in the refrigerator and storing

bacteria in a lyophyillized form?9. In which growth phase it produces large amounts of energy in the form of ATP in the

growth phase?10. How do we calculate number of bacteria using direct microscopic count?

Number of cells conted/volume of area11. Why do we put a blank before we measure the turbidity/optical density?12. In Krebs cycle, Electrons are picked up by NAD+ and FAD for the electron transport

chain. What are NAD+ and FAD?

13.

Exercise 1