Question 1

Which of the following statements best explains why ATP is considered the 'energy currency' of the cell?

Accepted Answer

ATP provides energy for cellular work by transferring a phosphate group to other molecules.

Question 2

A scientist measures the free energy change ($$\Delta G) of a $$reaction and finds $$\Delta G \u003c 0. $$Which of the following is true about this reaction?

Accepted Answer

It is exergonic and releases energy.

Question 3

Which of the following best describes the role of enzymes in biological reactions?

Accepted Answer

Enzymes lower the activation energy, speeding up the reaction.

Question 4

During cellular respiration, which process directly produces the most ATP?

Accepted Answer

Oxidative phosphorylation (ETC + chemiosmosis)

Question 5

A patient has a genetic mutation that prevents the formation of NADH during glycolysis. Which of the following would most likely occur as a result?

Accepted Answer

The electron transport chain would receive fewer electrons, reducing ATP production.

Question 6

Which of the following best explains why fermentation is important for cells under anaerobic conditions?

Accepted Answer

Fermentation regenerates NAD$$^+$$, allowing glycolysis to continue.

Question 7

In the light reactions of photosynthesis, what is the primary function of the electron transport chain?

Accepted Answer

To pump H$$^+$$ ions into the thylakoid space, creating a gradient for ATP synthesis.

Question 8

A competitive inhibitor affects an enzyme-catalyzed reaction by:

Accepted Answer

Binding to the active site and blocking substrate binding.

Question 9

Which of the following is a correct sequence of events in aerobic cellular respiration?

Accepted Answer

Glycolysis $$\rightarrow$$ Pyruvate Oxidation $$\rightarrow$$ Citric Acid Cycle $$\rightarrow$$ Oxidative Phosphorylation

Question 10

A plant is exposed to a toxin that inhibits ATP synthase in the thylakoid membrane. What is the most immediate effect on photosynthesis?

Accepted Answer

The plant will be unable to produce ATP during the light reactions.

Question 11

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

Accepted Answer

Exergonic reactions can be coupled to endergonic reactions to drive cellular processes.

Question 12

Which of the following is a real-life example of reaction coupling in human physiology?

Accepted Answer

ATP hydrolysis providing energy for active transport of sodium and potassium ions across the cell membrane.

Question 13

If a cell is deprived of oxygen, which of the following processes will be directly affected first?

Accepted Answer

Electron Transport Chain (ETC)

Question 14

Which of the following best explains why the Calvin Cycle is sometimes called the 'dark reactions'?

Accepted Answer

It does not require light directly and uses ATP and NADPH from the light reactions.

Question 15

A marathon runner's muscle cells switch to fermentation during the final sprint. What is the main product of this process in human muscle cells?

Accepted Answer

Lactic acid

Question 16

Which of the following best describes the specificity of enzymes?

Accepted Answer

Enzymes are substrate-specific due to the shape of their active site.

Question 17

Which of the following is a correct statement about the role of oxygen in cellular respiration?

Accepted Answer

Oxygen is the final electron acceptor in the electron transport chain.

Question 18

A noncompetitive inhibitor affects an enzyme by:

Accepted Answer

Binding to an allosteric site, changing the enzyme's shape and reducing activity.

Question 19

Which of the following best explains why the hydrolysis of ATP is highly exergonic?

Accepted Answer

The products (ADP and phosphate) have much lower free energy than ATP.

General Biology Study Guide: Metabolism, Cellular Respiration, Photosynthesis, Mitosis & Meiosis, Genetics

Guida di studio - Domande di pratica

Study guide - Flashcard