BIOL 2421 Microbiology                     Worksheet (25 points)              Name: ___________

Dr. Weis                                              Nutrition and Growth            Due Date: ________

1. Define nutrient; name and give examples of five (5) major macromolecule groups. (2)

2. Name eight (8) chemical elements, their atomic symbols, and give their use for microbial nutrition/growth. (2)

3. Draw with labels an expected microbial growth curve and specifically define each label on the curve and explain the processed happening with each labeled area. (2)

4. Define the following terms and then relate them to the cell membrane transport functions that are involved with these processes. (2)  

a. tonicity

b. osmosis

c. hydrostatic/hydraulic pressure

d. crenation

5.  Regarding pH: define mathematically, give the biological range, and name the three major categories of microbes based on their optimal pH requirements and examples of bacterial Genus & species for each pH category listed. (2)

6. Regarding temperature requirements: (3)

a. List and give the ranges for four categories of microbes based on temperature.

b. Give different Genus & species examples of bacteria for these four temperature groups.

c. Define optimum temperature and explain its importance to microbial growth.

d. Explain how temperature changes involved with metabolic functions.

7. Regarding oxygen classifications of microbes: (3)

a. Give the five major types of O2 microbial classifications.

b. Give bacterial Genus & species examples for each major classification type

c. Name two different media used to show/determine these classifications and explain the chemical reactions occurring in each media

d. Name three toxic forms of oxygen

e. Name two enzymes used to detoxify oxygen and the chemical reactions involved.

8. Name three direct as well as three indirect lab methods of measuring microbial growth; define and explain what is meant by MPN and when it is used clinically. (2)

9. Regarding culture media (2)

            a. Define selective media and give three different media examples.

            b. Define differential media and give three different media examples.

10. For question #9 examples listed, give the major ingredient(s) in each of these 6 media listed that causes each of these examples to be selective and/or differential, along with any pH or color indicator for these media. (3)

11. Define biofilms and quorum sensing. Give four different locations where this might occur and name two bacterial Genuses that are involved with or create biofilms. (2)