Chapter 18: Problem 41
What reduced coenzymes provide the electrons for electron transport?
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
NADH
The main function of NADH is to carry electrons to the electron transport chain (ETC).
By donating electrons, NADH becomes oxidized to NAD+. This process is essential for generating a proton gradient in the mitochondria.
NADH contributes significantly to ATP production, making it crucial for energy metabolism.
FADH2
FADH2 is produced during the Krebs cycle. It carries electrons to the ETC and donates them, turning back into FAD.
While both NADH and FADH2 are important, FADH2 produces fewer ATP molecules compared to NADH because it donates electrons further down the ETC.
This difference results in a lower proton gradient and consequently less ATP production.
Cellular Respiration
It consists of three main stages: Glycolysis, the Krebs cycle, and the Electron Transport Chain (ETC).
During glycolysis, glucose is broken down into two molecules of pyruvate, producing a small amount of ATP and NADH.
In the Krebs cycle, these pyruvate molecules undergo further breakdown, generating more NADH and FADH2.
Finally, in the ETC, the electrons from NADH and FADH2 travel through protein complexes in the mitochondrial membrane, ultimately leading to ATP production.
ATP Production
The majority of ATP is produced during the Electron Transport Chain (ETC).
Electrons from NADH and FADH2 are transferred through proteins in the mitochondrial membrane.
This process generates a proton gradient, which drives ATP synthesis.
It is estimated that each molecule of NADH can produce 2.5 ATP, while FADH2 produces about 1.5 ATP.
Thus, ATP production is tightly linked to the function of NADH and FADH2 in cellular respiration.
Proton Gradient
As electrons pass through the ETC, protons (H⁺ ions) are pumped from the mitochondrial matrix to the intermembrane space.
This creates a high concentration of protons outside the inner mitochondrial membrane compared to inside.
The gradient generates a potential energy difference, often referred to as the electrochemical gradient.
Protons flow back into the mitochondrial matrix through ATP synthase, a protein that synthesizes ATP using the energy from the proton movement.
Thus, the proton gradient is directly responsible for driving ATP production in cellular respiration.