Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Which of the following best describes the electron transport chain of cellular respiration?
A
A process that directly produces ATP by substrate-level phosphorylation in the cytoplasm.
B
A pathway that converts glucose into pyruvate in the cytoplasm.
C
A series of protein complexes that transfer electrons and pump protons to create a proton gradient across the inner mitochondrial membrane.
D
A cycle that oxidizes acetyl-CoA to carbon dioxide in the mitochondrial matrix.
Verified step by step guidance
1
Begin by understanding the role of the electron transport chain (ETC) in cellular respiration. It is the final stage of aerobic respiration, occurring in the inner mitochondrial membrane.
Recognize that the ETC involves a series of protein complexes and electron carriers. Electrons are transferred through these complexes, originating from NADH and FADH2 produced in earlier stages of respiration.
As electrons move through the chain, energy is released and used to pump protons (H+) from the mitochondrial matrix into the intermembrane space, creating a proton gradient.
This proton gradient generates a potential energy difference across the membrane, known as the proton motive force, which is crucial for ATP synthesis.
Finally, understand that ATP is produced when protons flow back into the matrix through ATP synthase, driven by the proton gradient. This process is known as oxidative phosphorylation, not substrate-level phosphorylation.