After Quiz 6

Question 1

What is meant by the concept of bacterial growth and what is the generation time?

Question 2

What does it mean that bacterial growth is exponential?

Question 3

You should be able to do a basic calculation of bacterial population growth (see equation on slide 3)

Question 4

What are the events that occur during binary fission (e.g. what happens to the cell wall/membrane, what happens to the genome, what is FtsZ and what does it do)?

Question 5

What is the function of transpeptidases and transglycosylases in terms of their role in peptidoglycan expansion (note these are often called penicillin binding proteins)? How does penicillin block this process?

Question 6

You need to know the difference between planktonic and biofilm growth and understand what characterizes each (e.g. what are properties of each type of growth)

Question 7

What occurs during quorum sensing? What is the purpose of it? What are autoinducers?

Question 8

You need to have a strong understanding of what occurs during the lag, log, stationary, and death phases of bacterial growth in closed systems? What characterizes each phase?

Question 9

Effect of temperature on bacterial growth – know the differences between psychrophiles, psychrotrophs, mesophiles, thermophiles, hyperthermophiles. What are some characteristics of each type of class?

Question 10

Effect of oxygen on bacterial growth – know the difference between obligate aerobes, obligate anaerobes, facultative anaerobes, microaerophiles, and aerotolerant anaerobes. What characterizes each class? Where do each grow when placed into a broth tube and WHY?

Question 11

Effect of pH on bacterial growth – what are different classes and what pH’s do each prefer?

Question 12

Effect of water availability on bacterial growth – what happens when bacteria are placed into excessively hypertonic environments? What are organisms called that can tolerate higher solute concentrations? Require high salt? Require very high salt?

Question 13

What are serial dilutions and why are they often necessary?

Question 14

What is meant by plate counting? What are benefits of plate counting? Drawbacks?

Question 15

What is the mean probable number and how is it determined?