4 An E coli culture is moved from a 37 C incubator which is

Last updated: 10/18/2023

4 An E coli culture is moved from a 37 C incubator which is its optimal growth temperature to a 42 C incubator which is the maximum temperature that will support growth This change in temperature will cause many changes in the cell Which of the following is NOT a change that you would expect to occur as a result of the increase in incubation temperature a The fluidity of the membrane will increase b E coli will begin to synthesize more chaperone proteins c The doubling time generation time of E coli will decrease d Some of the cellular proteins may begin to denature 5 When growing in a high salt environment halophilic bacteria synthesize or accumulate compatible solutes What is the function of these solutes a To prevent water from moving from the inside of the cell to the outside of the cell b To prevent water from moving from the outside of the cell to the inside of the cell c To bind excess Na and Cl ions that enter into the cell d To protect DNA from the corresponding increase of cellular Cl levels 6 Which of the following statements is FALSE regarding organisms and pH a In highly acidic environments organisms can increase their internal pH by utilizing an amino acid decarboxylase b In alkaline environments organisms can decrease their internal pH by utilizing a Na H antiporter c An acidophile will maintain a pH which is equal to the pH of its external environment d Most human pathogens would be classified as neutralophiles 7 Why do organisms that grow in the presence of oxygen require enzymes such as superoxide dismutase a These enzymes are required to reduce molecular oxygen to water in the last step of aerobic respiration b These enzymes are required to transport oxygen across the prokaryotic cell membrane c These enzymes neutralize reactive oxygen species that are generated as a byproduct of the metabolism of oxygen d These enzymes are required to decarboxylate organic acids 8 Staphylococcus aureus is able to respire aerobically if oxygen is available if oxygen is not available then S aureus is capable of supporting growth through fermentation How would we classify S aureus in terms of its oxygen tolerance a Obligate aerobe b Obligate anaerobe c Aerotolerant anaerobe d Facultative anaerobe