The combustion of glucose to yield carbon dioxide and water refers to aerobic metabolism (oxidative phosphorylation). This process releases energy, so Gibbs free energy is negative. A negative Gibbs free energy indicates that the products are at a lower energy than the reactants, meaning that the reaction is thermodynamically favorable (spontaneous). Lastly, aerobic metabolism is called so because it requires oxygen. Thus, all of the answers are correct.

The complexes that function as a part of the electron transport chain accept electrons from  and .  When they accept the high energy electrons, they also pump hydrogens across the mitochondrial inner membrane to ultimately be used at the ATP synthase.  Creation of ATP is the end goal, but it is not made directly by the electron transport chain complexes.

Oxygen is required for the electron transport chain to function because it is the final electron acceptor for oxidative respiration. Once the high energy electron carriers,  and , have delivered electrons to the chain, the electrons run through the protein complexes. When they finish moving through all of the complexes, something must be available for them to attach to. Oxygen is the molecule responsible for this. It accepts the electrons and in turn is converted into .

ATP synthase can indeed produce more than 100 ATP molecules per second, and in the process, it only requires a few -- three or four -- protons, per ATP. These protons pass down a gradient through the membrane. Hence, the protein is membrane-bound. The protons cause the rotor of 10-14 subunits to spin. The protein's head itself has six subunits, three of which have ADP binding and phosphate binding sites.

The electron transport chain moves high energy electrons through its complexes in order to create a proton gradient across the mitochondrial inner membrane.  The ATP synthase then uses this gradient to pass hydrogen atoms through it.  Because this is a favorable movement, it can be coupled to unfavorable processes such as conversion of ADP to ATP.  

ATP synthase catalyzes the reaction that shows ADP and the phosphate group forming ATP.  The hydrogen in the reactant side is the one involved in the proton gradient, and water is a byproduct of the reaction.

ATP synthase is located in the inner mitochondrial membrane. It has an F0 portion within the membrane and an F1 portion in the matrix. The F1 portion has a hexameric ring structure and is responsible for the creation of ATP from mechanical energy. The alpha, beta, and gamma subunits are all parts of the F1 portion of ATP synthase, however it is only the alpha and beta subunits that form the ring. Further, the beta subunit is the part of the ring that is considered to be catalytic.

First, let's consider the half reactions involved to determine . 

This overall reaction involves the donation of 2 electrons, so

 is defined as . The reaction we drew earlier is shown below:

We can see that  was oxidized and  was reduced. Find .

 is Faraday's constant, and is defined as: 

Solve for 

A positive Gibbs free energy implies that the process in question should be unfavorable under normal conditions.  The only process listed that is unfavorable and requires an input of energy is the pumping of hydrogen ions into the intermembrane space.  This occurs during the electron transport chain.

The phases of cellular respiration are glycolysis, pyruvate dehydrogenase complex, Krebs cycle, electron transport chain. Glycolysis produces a net total of 2 ATP, the Krebs cycle produces 1 GTP that is converted to ATP in another process, and the electron transport chain is where almost all of the ATP made in cellular respiration is formed. However, during the pyruvate dehydrogenase complex phase of cellular respiration, pyruvate is converted to acetyl-CoA as a preparation for the Krebs cycle, but no ATP is created.