Bios242 Exam 2 Study Guide With Complete Solutions

Chapter 7 1. What are the stages of the normal growth curve in a bacterial culture? -Lag phase: flat part of graph shows new cells adjusting, don’t appear to be growing. 1.) Exponential growth (log phase): growth curve increases dramatically 2.) Stationary phase: death rate and growth rate are equal. Graph plateaus. 3.) Death phase: Graph dips down. Cells die at a rapid rate. 2. What does optimal (optimum) growth temperature mean? -fastest rate of growth and metabolism. -between min. and max. 3. Know the different nutritional categories of microbes by energy and carbon source: a. Photoautotroph-Self feeder that uses inorganic carbon dioxide. Energy from sunlight. -Ex: algae, plants, cyanobacteria b. Chemoautotroph-Self feeder that uses inorganic carbon dioxide. Energy from inorganic chemicals. -Ex: methanogens(archaea!), deep sea vent bacteria c. Photoheterotroph-Feeds on autotrophs and uses organic carbon. Energy from sunlight. -Ex: purple and green photosynthetic bacteria d. Chemoheterotroph-Feeds on autotrophs and uses organic carbon. Energy from tissues fluids of living thing. *humans -Ex: animals, fungi, protozoa, bacteria, various parasites and pathogens 4. Know the different ecological groups by temperature of adaptation: a. Psychrophile-Cold lovers. Optimum: 5C b. Psychrotroph-Cold but not super cold. Refrigerator temp. c. Mesophile-Optimum: human body temp (37C). Most human pathogens. d. Thermophile-Hot lovers. Live in soil and water near volcanoes, compost piles, directly exposed to sun. Optimum: Above 45C. e. Extreme thermophile-Super hot. Also, know characteristics of each. 5. Know some other ecological groups by oxygen requirements: a. Aerobe-can use oxygen b. Facultative anaerobe-Does not require oxygen but will use it when present. c. Microaerophile-requires small amount of oxygen. d. Anaerobe-lack enzyme to use oxygen in respiration e. Aerotolerant anaerobe-do not use oxygen but can grow limited in its presence. 6. Know some other ecological groups by other growth requirements: a. Capnophiles-grow at higher CO2 b. Obligate acidophiles-require acidic environment. Molds and yeast; common food spoilage agents. c. Alkalinophiles-Live in hot pools and soils that contain high levels of basic minerals. d. Osmophiles-Live in environment with high solute concentration e. Obligate halophiles-require high salt environment f. Facultative halophiles-resistant to salt g. Barophiles-deep sea microbes that only exist in high pressures 7. Be able to determine the nutritional and physical requirements and ecological groups an organism belongs to based on its description. Please keep in mind that an organism can be part of more than one ecological group (ex. an organism might be both a hyperthermophile and an acidophile). Chapter 8 *OIL RIG. Oxidation is loss, reduction is gain. 8. What is the function of enzymes? Catalysts that overcome activation energy 9. What is activation energy? Required for chemical reaction to proceed. 10. What does an enzyme do to activation energy of a reaction? Lowers the activation energy. 11. What are the parts of an enzymes structure? What is a cofactor? What is a coenzyme? What are cofactors made of? What are coenzymes made of? -most composed of protein. Each has different primary structure, variations in folding, and unique active site. -Active site for target molecules (substrates) -regulatory site