ATP Synthase

I would like elaboration on a few of my test review questions please. They are not for a grade, I am more so interested in explanations.

13. What happens to the energy released in the electron transport chain?
   
A) It is used to polymerize sugars
B) It is all lost as heat   
C) It is used to phosphorylate ADP
D) It is used to produce H2O   
E) It is used to produce an H+ concentration gradient

27. What is the role of oxygen in oxidative phosphorylation?

A) Acts as an enzyme in ATP production   
B) Acts as the final electron acceptor   
C) Powers movement of protons through the membrane

31. What molecules release electrons into the electron transport chain?
   
A) Glucose and its metabolites   
B) ADP   
C) Acids   
D) NADH and FADH2

47. Where is the electron transport chain located?

A) In the mitochondrial matrix   
B) In the mitochondrial outer membrane
C) In the mitochondrial intermembrane space   
D) In the mitochondrial intermembrane

Thanks