Chapter 8

Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis?

100%

Starting with one molecule of glucose, glycolysis results in the net production of which of the following sets of energy-containing products?

2 NADH, 2 pyruvate, and 2 ATP

Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle?

3ATP, 6 CO2, 9 NADH, and 3 FADH2

In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the production of which of the following sets of molecules?

ATP, CO2, and ethanol (ethyl alcohol)

Which of the summary statements below describes the results of the following reaction?

C6H12O6 is oxidized and O2 is reduced.

Which of the following statements describes what happens to a molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction?

It loses electrons and loses potential energy.

Which of the following statements best describes the primary role played by oxygen in cellular respiration?

It serves as the final acceptor for electrons from the electron transport chain.

Which of the following statements about NAD+ is true?

NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle.

Following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is stored in the form of which of the following molecules?

NADH

What happens when electrons are passed from one atom to a more electronegative atom?

The more electronegative atom is reduced, and energy is released.

Why are carbohydrates and fats frequently considered high-energy foods?

They contain many electrons associated with hydrogen atoms.

The oxygen consumed during cellular respiration is directly involved in which of the following processes or events?

accepting electrons at the end of the electron transport chain

In chemiosmosis, what is the most direct source of energy that is used to convert ADP + Pi to ATP?

energy released from movement of protons through ATP synthase, down their electrochemical gradient

Which of the following sequences describes the path by which electrons travel downhill energetically in aerobic respiration?

glucose → NADH → electron transport chain → oxygen

A molecule becomes more oxidized when it __________.

loses an electron