1. Bacterial mutants that are unable to synthesize fatty acids will incorporate fatty acids into their membranes when fatty acids are supplied in their growth medium. Suppose that each of the two cultures contains a mixture of several types of straight-chain fatty acids, some saturated, and some unsaturated, ranging in chain length from 10-20 carbons. If one culture is maintained at 18°C and the other is maintained at 40° C over several generations, what differences in the composition of the cell membranes of the two cultures would you expect to observe? Explain your answer

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1. Clostridium butyricum does not appear to have superoxide dismutase (SOD) and catalase enzymes. How would the growth of C. butyricum in oxic conditions compare to its growth in anoxic conditions? On this basis, what is the aerotolerance category of C. butyricum? 2. Citrobacter freundii is a facultatively anaerobic bacterium. Why would you expect this bacterium to grow better (i.e. form larger colonies) in an oxic environment than in an anoxic one? (as a hint, do some research on the “Pasteur effect”)

Your roommate left the deviled eggs out on the counter for 8 hours, but is happily eating them for breakfast. "We learned that bacteria take 20 minutes to reproduce at room temperature," he explains, "so I figure at most there's only a couple hundred in there. No big deal." What is your response, after remembering the equation N Noert, and the fact that e is roughly equal to 2.72? %3D O The intrinsic rate of increase (r) is only equal to 2, since each bacterium divides in half. No big deal. Hand me a fork! O If just 1 dangerous bacterium landed on your egg at the beginning of the night, there would now be approximately 1.7 million. They have been growing exponentially all night! You might be okay, but better not risk it. O If just 1 dangerous bacterium landed on your egg at the beginning of the night, there would now be nearly 27 billion. They have been growing exponentially all night! Call me if you need a ride to the hospital later. So the population only doubled 3 times for every…