Q: Which equation best represents the summary reaction for aerobic cellular respiration?

$$\text{Glucose} + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O} + \text{ATP}$$

Question 1

Which of the following best describes the difference between Firmicutes and Actinobacteria, the two major phyla of Gram-positive bacteria?

Accepted Answer

Firmicutes have low G+C content, while Actinobacteria have high G+C content.

Question 2

A patient presents with symptoms of Rocky Mountain spotted fever. Which genus of bacteria is most likely responsible, and what is a unique characteristic of this group?

Accepted Answer

Rickettsia; it is an obligate intracellular bacterium spread by ticks.

Question 3

Which of the following statements about Enterobacteriales is correct?

Accepted Answer

They are Gram-negative rods, facultative anaerobes, ferment glucose, and reduce nitrate.

Question 4

Chlamydiae differ from Rickettsias in which of the following ways?

Accepted Answer

Chlamydiae have no peptidoglycan and no arthropod vectors, while Rickettsias have peptidoglycan and are transmitted by arthropod vectors.

Question 5

Which of the following genera is associated with the production of antibiotics and is distinguished by filamentous growth?

Accepted Answer

Streptomyces

Question 6

A culture of bacteria is growing at 37°C and shows optimal growth. Which term best describes these bacteria?

Accepted Answer

Mesophile

Question 7

Which of the following best explains why oxygen is considered a 'hot potato' for living cells?

Accepted Answer

Oxygen forms reactive oxygen species (ROS) such as superoxide and peroxide that can damage cells.

Question 8

Which type of culture media would you use to isolate bacteria that can ferment lactose, and how does it work?

Accepted Answer

Differential media; it shows differences in colony appearance based on lactose fermentation.

Question 9

Which biosafety level (BSL) would be appropriate for handling Staphylococcus aureus in a laboratory setting?

Accepted Answer

BSL-2

Question 10

During the quadrant streak plate method, what is the primary purpose of flaming the loop between quadrants?

Accepted Answer

To sterilize the loop and prevent cross-contamination, allowing for isolation of single colonies.

Question 11

Which equation best represents the summary reaction for aerobic cellular respiration?

Accepted Answer

$$	ext{Glucose} + 	ext{O}_2 ightarrow 	ext{CO}_2 + 	ext{H}_2	ext{O} + 	ext{ATP}$$

Question 12

Which of the following best describes the role of NAD$$^+$$ and FAD in cellular metabolism?

Accepted Answer

They are electron carriers involved in redox reactions.

Question 13

A bacterium is found growing only at the bottom of a broth tube and is killed by exposure to oxygen. Which term best describes this organism?

Accepted Answer

Obligate anaerobe

Question 14

Which of the following is a key difference between aerobic respiration, anaerobic respiration, and fermentation?

Accepted Answer

Aerobic respiration uses oxygen as the final electron acceptor, anaerobic respiration uses an inorganic molecule, and fermentation uses an organic molecule.

Question 15

Which of the following best describes feedback inhibition in metabolic pathways?

Accepted Answer

The final product of a pathway inhibits an early enzyme, preventing waste of energy and resources.

Question 16

Which of the following is NOT a direct method for measuring bacterial growth?

Accepted Answer

Turbidity measurement

Question 17

Which of the following best explains why semi-log paper is used to chart bacterial growth?

Accepted Answer

It allows exponential growth to be represented as a straight line, making analysis easier.

Question 18

Which of the following best describes the process of chemiosmosis in cellular respiration?

Accepted Answer

Protons (H$$^+) $$are pumped across a membrane, creating a gradient that drives ATP synthesis via ATP synthase.

Question 19

Which of the following organisms would be classified as a photoautotroph?

Accepted Answer

A plant that uses CO$$_2 as a $$carbon source and light as an energy source.

Question 20

Which of the following best describes the difference between homolactic and heterolactic fermentation?

Accepted Answer

Homolactic fermentation produces lactic acid only, while heterolactic fermentation produces lactic acid, CO$$_2$$, and ethanol.

Microbial Diversity, Growth, and Metabolism: Study Guide for Exam 2

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