Q: Which of the following reactions is an example of oxidation?

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

Question 1

Which of the following best describes the role of biosynthesis in cells?

Accepted Answer

It results in the formation of new chemical bonds and the synthesis of new molecules required for growth and maintenance.

Question 2

A muscle cell contracts to lift a weight. Which category of cellular work does this represent?

Accepted Answer

Mechanical work

Question 3

Which of the following is an example of concentration work in a cell?

Accepted Answer

The accumulation of digestive enzymes in secretory vesicles

Question 4

During neurotransmission, a neuron pumps Na+ ions out and K+ ions in, creating a membrane potential. What type of cellular work is this?

Accepted Answer

Electrical work

Question 5

Which of the following equations correctly expresses the change in internal energy ($$\Delta E) $$for a chemical reaction?

Accepted Answer

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

Question 6

Which statement about the first law of thermodynamics is correct?

Accepted Answer

Energy may be converted from one form to another but cannot be created or destroyed.

Question 7

A plant uses sunlight to convert $$CO_2$$ and $$H_2O$$ into $$C_6H_{12}O_6$ and O_2$. What type of organism is this and what process is occurring?

Accepted Answer

Photoautotroph; photosynthesis

Question 8

Which of the following reactions is an example of oxidation?

Accepted Answer

$$C_6H_{12}O_6$ + 6O_2 ightarrow 6CO_2 + 6H_2O + 	ext{energy}$$

Question 9

Which of the following best describes an exergonic reaction?

Accepted Answer

A reaction that yields energy and has $$\Delta G \u003c 0$$

Question 10

Which formula correctly relates free energy change ($$\Delta G$$), enthalpy change ($$\Delta H$$), and entropy change ($$\Delta S) at $$temperature $$T$$?

Accepted Answer

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

Question 11

Which of the following is true about entropy ($$S) in $$biological systems?

Accepted Answer

Entropy increases when a system becomes less ordered, such as when ice melts.

Question 12

A cell accumulates glucose against its concentration gradient. Which process is primarily responsible for this?

Accepted Answer

Active transport using ATP

Question 13

Which of the following statements about biological efficiency is correct?

Accepted Answer

Some energy is inevitably lost as heat, which can be used to maintain body temperature in homeotherms.

Question 14

Which of the following is NOT one of the four essential needs of every cell?

Accepted Answer

Oxygen as a final electron acceptor

Question 15

Which of the following best describes the difference between phototrophs and chemotrophs?

Accepted Answer

Phototrophs capture light energy and transform it into chemical energy, while chemotrophs obtain energy by oxidizing chemical bonds.

Question 16

Which of the following is a correct statement about open and closed systems in thermodynamics?

Accepted Answer

An open system can have energy added to or removed from it.

Question 17

Which of the following is an example of bioluminescence in biological systems?

Accepted Answer

The production of light by fireflies during courtship

Question 18

Which of the following equations represents the enthalpy ($$H) of a $$system?

Accepted Answer

$$H = E + PV$$

Question 19

A reaction has $$\Delta H \u003c 0$$ and $$\Delta G \u003c 0. $$Which of the following best describes this reaction?

Accepted Answer

Exothermic and exergonic

Question 20

Which of the following statements about the flow of energy and matter in the biosphere is correct?

Accepted Answer

Energy flows unidirectionally from the sun to the environment, while matter cycles between phototrophs and chemotrophs.

Chapter 5: Bioenergetics – The Flow of Energy in the Cell

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