Question 1

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP is the main energy currency, coupling exergonic and endergonic reactions.

Question 2

A ball is held at the top of a staircase and then released. Which statement correctly applies the laws of thermodynamics to this scenario?

Accepted Answer

The ball's potential energy is converted to kinetic energy, and some is lost as heat, illustrating the first and second laws of thermodynamics.

Question 3

Which of the following statements about redox reactions in cells is correct?

Accepted Answer

Redox reactions transfer electrons, often with protons, and are essential for harvesting energy from nutrients.

Question 4

Which of the following best explains why the hydrolysis of sucrose in water is extremely slow without an enzyme, even though it is exergonic?

Accepted Answer

The activation energy barrier is high, so the reaction rate is very low without an enzyme.

Question 5

A metabolic pathway is best described as:

Accepted Answer

A series of enzyme-catalyzed reactions that convert a specific molecule to a final product.

Question 6

Which of the following equations correctly represents the change in Gibbs free energy ($$\Delta G) $$for a chemical reaction?

Accepted Answer

$$\Delta G = G_{products} - G_{reactants}$$

Question 7

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

Accepted Answer

The synthesis of glucose from carbon dioxide and water during photosynthesis

Question 8

A cell is observed to have a high rate of ATP consumption. Which process must be occurring at a high rate to replenish ATP?

Accepted Answer

Phosphorylation of ADP using energy from catabolic (exergonic) reactions

Question 9

Which of the following best distinguishes autotrophs from heterotrophs?

Accepted Answer

Autotrophs can convert inorganic carbon (CO$$_2) $$into organic molecules, while heterotrophs must obtain organic carbon from their environment.

Question 10

Which of the following statements about the second law of thermodynamics is correct in the context of living cells?

Accepted Answer

Every energy transfer increases the entropy of the universe, and cells must use energy to maintain order.

Question 11

Which of the following is a correct statement about enzymes?

Accepted Answer

Enzymes speed up chemical reactions by lowering the activation energy barrier.

Question 12

A patient is unable to efficiently break down glucose for energy. Which cellular process is most likely impaired?

Accepted Answer

Catabolic pathways that harvest energy via redox reactions

Question 13

Which of the following best describes the ATP cycle in a working muscle cell?

Accepted Answer

ATP is continuously regenerated from ADP and $$P_i$$ using energy from catabolic reactions.

Question 14

Which of the following is a real-life example of a redox reaction important for cellular energy?

Accepted Answer

The transfer of electrons from glucose to NAD$$^+$$, forming NADH during cellular respiration

Question 15

If a reaction has a negative $$\Delta G$$, which of the following is true?

Accepted Answer

The reaction is exergonic and can occur spontaneously.

Question 16

Which of the following best explains why cells do not use all the energy from glucose at once?

Accepted Answer

Cells package energy into ATP, a chemical form that is accessible and manageable for cellular work.

Question 17

Which of the following is a correct pairing of metabolic process and its description?

Accepted Answer

Catabolism: breakdown of molecules to produce ATP

Question 18

Which of the following best describes the function of NAD$$^+ in $$cellular metabolism?

Accepted Answer

NAD$$^+$$ acts as an electron acceptor, becoming reduced to NADH during catabolic reactions.

Question 19

A scientist measures the entropy of a system before and after a chemical reaction. According to the second law of thermodynamics, what should they expect?

Accepted Answer

The total entropy of the universe will increase, even if the system's entropy decreases.

Chapter 8: Energy and Metabolism – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard