What are the functions of the high -energy electrons in the electron transport chain? (point) They hold water bonds. They create ATP synthase. They make ATP from ADP They carry NADH and FAD*H_{2}
The correct functions of high-energy electrons in the electron transport chain are:
1. They carry energy from food molecules: High-energy electrons are transferred from NADH and FADH2 to electron carriers embedded in the inner mitochondrial membrane. These electrons are obtained from the breakdown of food molecules such as glucose during cellular respiration.
2. They generate a proton gradient: As the high-energy electrons move through the electron transport chain, they pass through a series of protein complexes. This movement results in the pumping of protons across the inner mitochondrial membrane, creating a gradient of protons or a proton motive force.
3. They create ATP synthase: The proton motive force generated by the high-energy electrons is used by ATP synthase enzyme to produce ATP. As protons flow back into the inner mitochondrial membrane through ATP synthase, it drives the synthesis of ATP from ADP (adenosine diphosphate) and inorganic phosphate.
So, out of the given options:
- They hold water bonds: This is incorrect as high-energy electrons do not hold water bonds.
- They create ATP synthase: This is incorrect as ATP synthase is an enzyme that uses proton motive force to produce ATP, not high-energy electrons.
- They make ATP from ADP: This is correct. High-energy electrons, through their movement and the resulting proton gradient, supply the energy required for ATP synthesis.
- They carry NADH and FADH2: This is correct. High-energy electrons are carried by NADH and FADH2, which were initially generated in earlier stages of cellular respiration.
The high-energy electrons in the electron transport chain serve several important functions.
First, they carry NADH and FADH2 molecules, which are produced during earlier stages of cellular respiration, to the electron transport chain. These high-energy electron carriers donate their electrons to the electron transport chain, allowing the chain to proceed.
As electrons move through the electron transport chain, energy is released in a series of redox reactions. This energy is used by complexes in the electron transport chain to pump protons across the inner mitochondrial membrane, creating a proton gradient.
The high-energy electrons also play a crucial role in the production of ATP. As the electron transport chain progresses, the energy released by the electrons is used to power ATP synthase, an enzyme located in the inner mitochondrial membrane. ATP synthase uses the energy from the flowing electrons to catalyze the synthesis of ATP from ADP (adenosine diphosphate) and inorganic phosphate.
Lastly, the high-energy electrons help maintain the stability of water molecules in the electron transport chain. Oxygen molecules act as the final electron acceptor in the chain, and the high-energy electrons combine with protons and oxygen to form water. This is why oxygen is necessary for aerobic respiration.
In summary, the functions of high-energy electrons in the electron transport chain include carrying electron carriers, creating a proton gradient, powering ATP synthesis, and participating in the formation of water molecules.