Figure 9.3
-What happens at the end of the chain in Figure 9.3?
A) 2 electrons combine with a proton and a molecule of NAD⁺.
B) 2 electrons combine with a molecule of oxygen and two hydrogen atoms.
C) 4 electrons combine with a molecule of oxygen and 4 protons.
D) 4 electrons combine with four hydrogen and two oxygen atoms.
E) 1 electron combines with a molecule of oxygen and a hydrogen atom.

Question

Figure 9.3
-What happens at the end of the chain in Figure 9.3?
A) 2 electrons combine with a proton and a molecule of NAD⁺. 
B) 2 electrons combine with a molecule of oxygen and two hydrogen atoms. 
C) 4 electrons combine with a molecule of oxygen and 4 protons. 
D) 4 electrons combine with four hydrogen and two oxygen atoms. 
E) 1 electron combines with a molecule of oxygen and a hydrogen atom.

Quizplus · Accepted Answer

At the end of the electron transport chain, 4 electrons combine with a molecule of oxygen and 4 protons to form water. This is a key step in the process of oxidative phosphorylation, which occurs in the mitochondria of cells.

Figure 9.3 -What Happens at the End of the Chain in Figure