Suppose that you were tasked with 4 cultures of a specific Bacteria Species in Luria Broth medium: (1) culture A – cells are in lag phase; (2) culture B – cell in log phase; (3) culture C – cells in stationary phase; and culture D – cells in decline phase. Imagine that you observe the growth rates of each culture in a fresh sterilized LB medium. Now, plot the outcome growth curves of cultures A, B, C and D in a single graph.

4. (a) Which of the following chemical reactions is an overall oxidation-reduction (redox) reaction that involves oxidation number changes in their reactions? A. NaOH + H₂O → Na¹ + H3O+ + OH B. HCl + H₂O → H3O+ + Cl- C. CO₂ + H₂O → H+ + CO3²- D. N₂ + 3H₂ → 2NH3

1. Plate count data are used to calculate microbial population density as colony forming units (CFUs) per milliliter of culture. Culture density (CFU/mL) = number of colonies (dilution factor) x (volume plated, in mL) Use these data below to calculate the CFU/mL in this sample of bacteria after 1 hr of growth. **Important to know for these types of questions - only use colony counts that fall between 10 and 300. TNTC = too numerous to count, so many colonies that you can't distinguish them to count. Use the plates with numbers of colonies that can be counted, calculate the CFU on each one, and then calculate the average between all of them. Looking for more assistance? Read section 7.3 in the textbook. Time 1h Dilution (before plating) Volume spread on plate 0.1 mL 0.1 mL 0.1 mL 0.1 mL none 1:10 (1 x 10-¹) 1:100 (1 x 10-²) 1:1,000 (1 x 10-³) Number of colonies observed (replicate plates) TNTC 499 83 10 TNTC 518 87 8 TNTC indicates too numerous to count. *Cell density could not be…

All of the following are valid measurements of growth except: A. Counting viable cells B. Estimating the weight of cells C. Determining the dry weight of cells D. Streaking for single colonies E. Measuring some cellular component F. Counting the total number of cells

Two bacterial species have generation times of 20 min and 18 hours respectively. From the below list, choose all true statements. A. The 2nd species must not be at the optimal temperature for its growth B. different species may have very different generation times  C. optimal culture conditions may not have been used for one or both species D. stationary phase will be reached much faster with the first species

B) A total of 2.5 x 105 cells were harvested from the patient. You need the cells to fill a scaffold with dimensions of 20mm x 20mm x 4mm at a final density of 2 x 104 cells/mm³. After culturing the harvested cells, you found that they have a doubling time of 36 hours. Determine the total number of cells (N) needed to fill the scaffold. Show your work.

Use the following passage to answer 2 consecutive questions. A urine specimen was collected in a container and placed on the central desk for delivery at 10:00 am. The specimen is not sent to the lab until 5 hours later (3:00 pm). The sample time was marked by the central clerk as collected at 4:00 pm. The bacterial species has a generation time of 30 minutes at room temperature. There are 100 bacterial cells/ml at the time of collection (10:00 am). The laboratory will cite a bacterial infection at more than 1000 bacterial cells/ml.

Based on the growth curve, which ONE of the following best describes what would happen if sample of culture in the presence of drug B is inoculated onto drug-free growth medium?   Select one: A.   Growth present, but cell count increased by at least 99.9% of the original culture   B. No growth after 24 hrs C. Growth at 24 hrs D. Not possible to predict because the culture could either be alive or dead E. Growth present, but cell count reduced by at least 99.9% of the original culture

What would the final concentration of a bacteria culture be if 2.7 x 106 cells/ml were diluted 8.2 x 10-2?  What would the initial concentration of a bacteria culture be if the final concentration was 3.7 x 102 cells/ml and the total dilution was 4.6 x 10-4?

B) A total of 2.5 x 105 cells were harvested from the patient. You need the cells to fill a scaffold with dimensions of 20mm x 20mm x 4mm at a final density of 2 x 104 cells/mm³. After culturing the harvested cells, you found that they have a doubling time of 36 hours. Given the growth rate is proportional to the number of cells, determine the time it will take to achieve the desired cell count. Show your work.