Question 1

Which of the following best describes biosynthetic work in cells?

Accepted Answer

Formation of new chemical bonds and synthesis of new molecules

Question 2

A ciliated cell in the trachea expends energy to sweep inhaled particles away from the lungs. This is an example of which kind of cellular work?

Accepted Answer

Mechanical work

Question 3

Which process requires energy to move molecules from a region of low concentration to high concentration across the plasma membrane?

Accepted Answer

Concentration work

Question 4

The active outward transport of ions across a cellular membrane is crucial for which of the following processes?

Accepted Answer

Generation of membrane potential for ATP production

Question 5

Which equation correctly represents the change in internal energy ($$\Delta E) $$during a chemical reaction?

Accepted Answer

$$\Delta E = E_{products} - E_{reactants}$$

Question 6

Which of the following is true about open systems in biological contexts?

Accepted Answer

They require a constant influx of energy to maintain complexity.

Question 7

Which formula expresses the relationship between enthalpy ($$H$$), internal energy ($$E$$), pressure ($$P$$), and volume ($$V$$)?

Accepted Answer

$$H = E + PV$$

Question 8

A reaction has a negative $$\Delta H$$ and a positive $$\Delta S at $$constant temperature. What can be said about the spontaneity of the reaction?

Accepted Answer

It is always spontaneous.

Question 9

Which equation defines the change in free energy ($$\Delta G) in $$terms of enthalpy and entropy?

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$

Question 10

Which of the following statements about equilibrium in cellular reactions is correct?

Accepted Answer

A cell at equilibrium is considered dead because no net work is performed.

Question 11

Which type of organism obtains energy by oxidizing inorganic compounds and synthesizes all organic compounds from $$CO_2$$?

Accepted Answer

Chemoautotroph

Question 12

What is the main difference between phototrophs and chemotrophs?

Accepted Answer

Phototrophs capture energy from sunlight, while chemotrophs obtain energy by oxidizing chemical bonds.

Question 13

Which of the following reactions is an example of oxidation?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 \rightarrow 6CO_2 + 6H_2O + energy$$

Question 14

Which of the following best describes the second law of thermodynamics in biological systems?

Accepted Answer

Spontaneous processes result in an increase in the entropy of the universe.

Question 15

If a reaction in a cell has $$\Delta G \u003c 0$$, what does this indicate?

Accepted Answer

The reaction is exergonic and can proceed spontaneously.

Question 16

Which of the following is a real-world example of electrical work in cells?

Accepted Answer

Transmission of nerve impulses via membrane potential

Question 17

Which of the following is NOT one of the six kinds of cellular work described in bioenergetics?

Accepted Answer

Passive diffusion

Question 18

Which of the following best explains why heat is not a useful form of energy for most biological systems?

Accepted Answer

Biological systems operate under isothermal conditions and lack temperature gradients required to convert heat into work.

Question 19

Which of the following statements about steady state in cells is correct?

Accepted Answer

Cells maintain reactions far from equilibrium by constant energy input, allowing cellular work to continue.

Chapter 5

Study Guide - Practice Questions