Cellular Respiration

What is the term used for the metabolic pathway in which glucose (C₆H₁₂O₆) is degraded to carbon dioxide (CO₂) and water?

• oxidative phosphorylation

• cellular respiration

• glycolysis

• fermentation

All of the following are functions of the citric acid cycle EXCEPT

• addition of electrons and protons to oxygen to form water.

• production of ATP.

• release of carbon dioxide.

• production of NADH.

How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate?

• eight carbon atoms

• six carbon atoms

• four carbon atoms

• two carbon atoms

In glycolysis, for each molecule of glucose oxidized to pyruvate

• two molecules of ATP are used and two molecules of ATP are produced.

• two molecules of ATP are used and four molecules of ATP are produced.

• two molecules of ATP are used and six molecules of ATP are produced.

• four molecules of ATP are used and two molecules of ATP are produced.

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The ATP made during glycolysis is generated by

• electron transport.

• chemiosmosis

• substrate-level phosphorylation.

• photophosphorylation.

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Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?

• The covalent bond in oxygen is unstable and easily broken by electrons from organic molecules.

• The covalent bonds in organic molecules are higher energy bonds than those in water and carbon dioxide.

• The electrons have a higher potential energy when associated with water and carbon dioxide than they do in organic compounds.

• Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O).

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Which of the following statements is correct about an oxidation-reduction (or redox) reaction?

• The molecule that is oxidized loses protons.

• The molecule that is reduced loses electrons.

• The molecule that is reduced gains electrons.

• The molecule that is reduced gains electrons.

When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the

• formation of ATP.

• restoration of the Na⁺/K⁺ balance across the membrane.

• reduction of NAD⁺.

• creation of a proton gradient.

The primary role of oxygen in cellular respiration is to

• combine with lactate, forming pyruvate.

• combine with carbon, forming CO₂.

• act as an acceptor for electrons and hydrogen, forming water.

• yield energy in the form of ATP as it is passed down the respiratory chain.

Where are the proteins of the electron transport chain located?

• cytosol

• mitochondrial inner membrane

• mitochondrial intermembrane space

• mitochondrial matrix