Weekly Worksheet 3.docx

BIOL 2303: Microbiology Weekly Worksheet 3 Name/ID: _______________________ MIDTERM- STYLE QUESTIONS 1. For the following question, you must use two formulae: g = t/n N n = N 0 x 2 n *Where n = # of generations, N 0 = number of cells in the flask at the beginning (i.e., time zero), N n = number of cells in the flask after n generations, g = generation time where time (t) is in min or hr. The question requires you to solve for one of the variables: g, t, n, N, or N o . A strategy for tackling these questions can be to identify which variables you have been given and then solve for the remaining one. In most cases you will have to use both equations. a) You inoculate a flask of fresh medium with 5x10 4 exponentially growing bacterial cells and after 4 hours you have 6x10 10 cells. i. How many generations have the bacteria gone through? about 20.2 generations ii. What is the generation time for the bacterial culture under these conditions? the generational time is 0.2 hours b) You inoculate a flask of fresh medium with 3x10 4 exponentially growing bacterial cells and after 5 hours you have 8x10 8 cells. What is the generation time of this bacterial culture? the generational time is 0.34 hours c) Given the same question above in (b), how many cells would you have if the bacterium that you used for inoculation has a generation time of 30 min ? (Hint - either convert the 5 hours to min or the 30 min to hours) about 30720000 cells 2. Name two cellular processes/features that may be affected by changes in temperature or oxygen availability. Two cellular processes that may be affected by changes in temperature or oxygen availability may include cellular respiration and protein folding. BIOL2023_Winter2024