$$\Delta G0' = Gf0[\text{products}] - Gf0[\text{reactants}]$$

Phosphorus – $$\text{PO}_4$$^{3-}$$

Question 1

Which macromolecule makes up the largest percentage of a typical cell's dry weight?

Accepted Answer

Protein

Question 2

A bacterium is growing in an environment with very low iron availability. Which adaptation is it most likely to use to acquire iron?

Accepted Answer

Synthesis of siderophores

Question 3

Which of the following best describes the function of an enzyme in a metabolic reaction?

Accepted Answer

It lowers the activation energy required for the reaction.

Question 4

Which equation correctly describes the calculation of the standard Gibbs free energy change for a reaction?

Accepted Answer

$$\Delta G0' = Gf0[	ext{products}] - Gf0[	ext{reactants}]$$

Question 5

Which of the following is a micronutrient required by some microorganisms?

Accepted Answer

Iron

Question 6

A microbe that uses CO2 as its sole carbon source and obtains energy by oxidizing inorganic compounds is best classified as a:

Accepted Answer

Chemolithoautotroph

Question 7

Which of the following statements about the redox tower is TRUE?

Accepted Answer

The greater the drop between donor and acceptor, the more energy is released.

Question 8

Which of the following is a high-energy compound used for energy storage in cells?

Accepted Answer

Acetyl-CoA

Question 9

In the reaction $$	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6	ext{O}_2 ightarrow 6	ext{CO}_2 + 6	ext{H}_2	ext{O}$$, which molecule is oxidized?

Accepted Answer

Glucose

Question 10

Which of the following best describes the role of NAD+ in cellular metabolism?

Accepted Answer

It serves as a diffusible electron carrier, accepting electrons during catabolic reactions.

Question 11

Which of the following is a correct pairing of a macronutrient and its usual environmental form?

Accepted Answer

Phosphorus – $$	ext{PO}_4$$^{3-}$$

Question 12

A bacterium stores excess carbon in the form of poly-β-hydroxybutyrate (PHB) granules. What is the main advantage of this storage strategy?

Accepted Answer

It allows the cell to store carbon in an insoluble form, reducing osmotic stress.

Question 13

Which of the following best describes the difference between fermentation and respiration?

Accepted Answer

Fermentation uses substrate-level phosphorylation, while respiration uses oxidative phosphorylation.

Question 14

Which of the following is TRUE about the function of the FtsZ protein in bacterial cell division?

Accepted Answer

It forms a contractile ring at the mid-cell, guiding septum formation.

Question 15

Which environmental factor is most likely to limit the growth of a halophile?

Accepted Answer

Low salt concentration

Question 16

Which of the following best explains why oxygen can be toxic to some microorganisms?

Accepted Answer

Oxygen can be converted to reactive byproducts that damage macromolecules.

Question 17

Which enzyme is responsible for detoxifying hydrogen peroxide in aerobic bacteria?

Accepted Answer

Catalase

Question 18

A bacterium is classified as a facultative anaerobe. Which of the following best describes its growth characteristics?

Accepted Answer

It grows in the presence or absence of oxygen, but prefers oxygen if available.

Question 19

Which of the following best describes the role of the MinCDE system in bacterial cell division?

Accepted Answer

It ensures the FtsZ ring forms at the mid-cell by preventing its formation at the poles.

Question 20

Which of the following is a correct description of the relationship between reduction potential and free energy change in redox reactions?

Accepted Answer

$$\Delta G0' = -nF\Delta E0'$$

Microbial Metabolism, Nutrition, Bioenergetics, and Growth

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