Question 1

A student drops his notes, and his papers scatter. The fact that the papers scatter and do not remain neatly stacked is an illustration of

Accepted Answer

The scattering of papers illustrates an increase in entropy and aligns with the second law of thermodynamics, which states that the total entropy of an isolated system can never decrease over time.

Question 2

Nerve impulses travel along the neurons by the opening of channels that allow sodium ions to flow inward followed by an outward flow of potassium ions. In order to ensure that the impulse may be produced at any time, sodium is actively transported out of the cell, and potassium is transported into the cell by the sodium/potassium pump. Which of the following types of work is performed by the sodium/potassium pump?

Accepted Answer

The sodium/potassium pump performs concentration work by actively transporting sodium and potassium ions across the cell membrane to maintain concentration gradients.

Question 3

Muscle contraction is an example of which of the following types of work?

Accepted Answer

Muscle contraction is an example of mechanical work, as it involves the physical movement of muscles.

Question 4

The statement, "Energy is neither created or destroyed," describes

Accepted Answer

The statement describes the law of conservation of energy, which is synonymous with the first law of thermodynamics.

Question 5

In a cell, the concentration of glucose- 6- phosphate is 83 µM and fructose- 6- phosphate is 14 µM. The OG°' = 410 cal/mol for the conversion of glucose- 6- phosphate to fructose- 6- phosphate. Based upon this information, the OG' for this reaction (in cal/mol)is

Accepted Answer

The answer of In a cell, the concentration of glucose-...

Question 6

Oxidation

Accepted Answer

The answer of Oxidation
...

Question 7

Which of the following is a phototroph?

Accepted Answer

A tree is a phototroph because it uses sunlight to produce energy through photosynthesis.

Question 8

Under the conditions of a given reaction, a positive OG' means

Accepted Answer

A positive Gibbs free energy change (ΔG') indicates that the reaction is non-spontaneous under the given conditions, meaning it will not occur without the input of energy.

Question 9

A spontaneous reaction

Accepted Answer

A spontaneous reaction is one that can occur without external input, but it does not necessarily happen quickly; it may take a long time to proceed.

Question 10

Which of the following is not a basic need of the cell?

Accepted Answer

Cells do not require 100% efficiency to function. They need chemical catalysts, information, molecular building blocks, and energy to carry out essential processes.

Question 11

In a chemical reaction, the standard free energy change (OG°')is calculated to be 3.67 cal/mol. What can be said of the chemical reaction?

Accepted Answer

A positive standard free energy change (ΔG°') indicates that the reaction is not spontaneous under standard conditions.

Question 12

In a reversible chemical reaction at equilibrium, the concentration of X (the reactant)is 0.75 moles/liter, and the concentration of Y (the product)is 2.25 moles/liter. At 25° C, what would be the Keq?

Accepted Answer

The equilibrium constant (Keq) is calculated using the formula Keq = [products]/[reactants]. Here, Keq = [Y]/[X] = 2.25/0.75 = 3.0.

Question 13

When OG' = 0 in a chemical reaction, under the conditions

Accepted Answer

When ΔG' = 0, the reaction is at equilibrium, meaning no net change occurs, and no work can be done as no energy is required to maintain the reaction.

Question 14

When the OG°' of a chemical reaction is positive (K'eq < 1.0)under standard conditions,

Accepted Answer

When the standard Gibbs free energy change (ΔG°') is positive, the reaction is non-spontaneous under standard conditions, meaning that reactants predominate over products, and the equilibrium constant (K'eq) is less than 1.

Question 15

Bioenergetics can be simply defined as

Accepted Answer

Bioenergetics is the study of the transformation of energy in living organisms, which is essentially applied thermodynamics in biological systems.

Question 16

Which of the following types of work involves a change in position of the cell or a cell structure?

Accepted Answer

Mechanical work involves a change in position of the cell or a cell structure.

Question 17

The voodoo lily (Sauromatum gattatum)is able to

Accepted Answer

The voodoo lily emits a foul odor similar to rotting meat to attract flies, which are its pollinators. It also uses metabolic heat to help disperse the odor, making all the options correct.

Question 18

Which of the following is defined as "heat content?"

Accepted Answer

Enthalpy is defined as the total heat content of a system.

Question 19

Matter and energy flow through the biosphere. The flow of matter, however, differs from the flow of energy. Which of the following statements accurately describes these differences?

Accepted Answer

Matter flows in cycles, whereas energy flows in one direction.

Question 20

A negative free energy change indicates that

Accepted Answer

A negative free energy change indicates that the reaction is spontaneous and releases energy, which is characteristic of an exothermic reaction.

Quiz 5: Bioenergetics: The Flow of Energy in the Cell