Daily Newsletter February 23, 2012

Daily Newsletter February 22, 2012

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Today's Topic: The Respiratory Chain

In class today, we talked about the citric acid cycle and the respiratory chain. Below you will find some major points that I want you to remember:

• The major way that energy is harvested is through redox reactions.
• When needed for ATP production, electron carriers transfer electrons to the respiratory chain (electron transport chain) on the inner mitochondrial membrane.
• Complex I, III, and IV are transmembranal electron transporters that serve as proton pumps.
• The second law of thermodynamics is important in the respiratory chain.
• As electrons pass between carriers, they loose energy.
• They move from excited back to ground state.
• When an electron is close to ground state, we need to give it to a terminal electron acceptor.
• Eukaryotes use oxygen as a terminal electron acceptor.
• Oxygen + 2 electrons + 2 Hydrogens produces water.
• With out a terminal electron acceptor, the respiratory chain backs up.
• Prokaryotes can use different electron acceptors.
• When electrons move between transmembranal electron transporters, hydrogen is pumped to the intermembranal spaces (mitochondria).
• You create a proton motive force (electrochemical gradient).
• As ions move down their electrochemical gradient, across a membrane, work is done.
• The proton motive force powers ATP synthesis.

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Daily Challenge: The Respiratory Chain
Your task to day is to reflect and write about oxidative phosphorylation: the use of a respiratory chain and proton motive force to regenerate ATP. Start with NADH + H⁺ from the citric acid cycle (mitochondrial matrix).