Q: Which equation best represents the increase in entropy during the breakdown of glucose in cellular respiration?

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

Question 1

Which of the following best describes the role of mitochondria in muscle cells during marathon training?

Accepted Answer

They increase the cell's ability to metabolize glucose by increasing in number.

Question 2

Which of the following is an example of potential energy in a biological system?

Accepted Answer

A molecule of glucose before it is broken down in cellular respiration.

Question 3

According to the first law of thermodynamics, which of the following statements is true?

Accepted Answer

Energy cannot be created or destroyed, only transformed from one form to another.

Question 4

A roller-coaster car at the top of a hill is an example of which type of energy?

Accepted Answer

Potential energy

Question 5

Which equation best represents the increase in entropy during the breakdown of glucose in cellular respiration?

Accepted Answer

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

Question 6

Which of the following statements about exergonic and endergonic reactions is correct?

Accepted Answer

Exergonic reactions release energy, while endergonic reactions require a net input of energy.

Question 7

ATP is often described as the 'energy currency' of the cell. Which process best explains how ATP stores energy?

Accepted Answer

Energy from exergonic reactions is used to add a phosphate group to ADP, forming ATP.

Question 8

Which of the following best describes the function of enzymes in biological systems?

Accepted Answer

They lower the activation energy required for chemical reactions to proceed.

Question 9

A patient is given a drug that acts as a competitive inhibitor for an enzyme. What is the most likely effect of this drug?

Accepted Answer

It binds to the active site of the enzyme, preventing the normal substrate from binding.

Question 10

Which of the following environmental changes is most likely to denature a human enzyme?

Accepted Answer

A sustained increase in temperature above $$37^\circ C$$

Question 11

Which of the following is an example of a coupled reaction in a cell?

Accepted Answer

The energy released from the breakdown of glucose is used to synthesize ATP from ADP and $$P_i.$$

Question 12

Why do living organisms require a constant input of energy from the environment?

Accepted Answer

To maintain order and counteract the natural tendency toward increased entropy.

Question 13

Which of the following best explains why salt is used to preserve food?

Accepted Answer

Salt slows enzyme-catalyzed reactions that allow bacteria and fungi to grow.

Question 14

Which of the following is true about metabolic pathways?

Accepted Answer

They are series of chemical reactions, each catalyzed by a specific enzyme.

Question 15

A scientist adds a noncompetitive inhibitor to an enzyme-catalyzed reaction. What is the most likely result?

Accepted Answer

The inhibitor binds to a site other than the active site, causing the enzyme to change shape and become less active.

Question 16

Which of the following best describes the relationship between exergonic and endergonic reactions in cells?

Accepted Answer

Exergonic reactions provide the energy required to drive endergonic reactions, often through intermediates like ATP.

Question 17

Which of the following is NOT a function of ATP in the cell?

Accepted Answer

Long-term energy storage

Question 18

Which of the following best explains why enzymes are highly specific for their substrates?

Accepted Answer

The shape and chemical properties of the enzyme's active site match only certain substrates.

Question 19

A marathon runner's muscle cells have increased numbers of mitochondria and capillaries. Which of the following best explains the advantage of these adaptations?

Accepted Answer

They enhance the cell's ability to produce ATP by increasing glucose metabolism and oxygen delivery.

Question 20

Which of the following is a real-world example of enzyme inhibition with medical relevance?

Accepted Answer

Penicillin inhibits an enzyme needed to synthesize bacterial cell walls.

Energy Flow in the Life of a Cell: Chapter 6 Study Notes

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